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Checking references for intended status: Informational ---------------------------------------------------------------------------- -- Looks like a reference, but probably isn't: '0' on line 252 -- Looks like a reference, but probably isn't: '180' on line 252 == Missing Reference: 'Cycle-ID' is mentioned on line 1062, but not defined == Outdated reference: A later version (-06) exists of draft-ietf-lmap-use-cases-05 == Outdated reference: A later version (-24) exists of draft-ietf-ippm-metric-registry-01 == Outdated reference: A later version (-18) exists of draft-ietf-lmap-information-model-03 Summary: 0 errors (**), 0 flaws (~~), 5 warnings (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group P. Eardley 3 Internet-Draft BT 4 Intended status: Informational A. Morton 5 Expires: July 18, 2015 AT&T Labs 6 M. Bagnulo 7 UC3M 8 T. Burbridge 9 BT 10 P. Aitken 11 Brocade 12 A. Akhter 13 LiveAction 14 January 14, 2015 16 A framework for large-scale measurement platforms (LMAP) 17 draft-ietf-lmap-framework-10 19 Abstract 21 Measuring broadband service on a large scale requires a description 22 of the logical architecture and standardisation of the key protocols 23 that coordinate interactions between the components. The document 24 presents an overall framework for large-scale measurements. It also 25 defines terminology for LMAP (large-scale measurement platforms). 27 Status of This Memo 29 This Internet-Draft is submitted in full conformance with the 30 provisions of BCP 78 and BCP 79. 32 Internet-Drafts are working documents of the Internet Engineering 33 Task Force (IETF). Note that other groups may also distribute 34 working documents as Internet-Drafts. The list of current Internet- 35 Drafts is at http://datatracker.ietf.org/drafts/current/. 37 Internet-Drafts are draft documents valid for a maximum of six months 38 and may be updated, replaced, or obsoleted by other documents at any 39 time. It is inappropriate to use Internet-Drafts as reference 40 material or to cite them other than as "work in progress." 42 This Internet-Draft will expire on July 18, 2015. 44 Copyright Notice 46 Copyright (c) 2015 IETF Trust and the persons identified as the 47 document authors. All rights reserved. 49 This document is subject to BCP 78 and the IETF Trust's Legal 50 Provisions Relating to IETF Documents 51 (http://trustee.ietf.org/license-info) in effect on the date of 52 publication of this document. Please review these documents 53 carefully, as they describe your rights and restrictions with respect 54 to this document. Code Components extracted from this document must 55 include Simplified BSD License text as described in Section 4.e of 56 the Trust Legal Provisions and are provided without warranty as 57 described in the Simplified BSD License. 59 Table of Contents 61 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 62 2. Outline of an LMAP-based measurement system . . . . . . . . . 5 63 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 9 64 4. Constraints . . . . . . . . . . . . . . . . . . . . . . . . . 12 65 4.1. The measurement system is under the direction of a single 66 organisation . . . . . . . . . . . . . . . . . . . . . . 13 67 4.2. Each MA may only have a single Controller at any point in 68 time . . . . . . . . . . . . . . . . . . . . . . . . . . 13 69 5. Protocol Model . . . . . . . . . . . . . . . . . . . . . . . 13 70 5.1. Bootstrapping process . . . . . . . . . . . . . . . . . . 14 71 5.2. Control Protocol . . . . . . . . . . . . . . . . . . . . 15 72 5.2.1. Configuration . . . . . . . . . . . . . . . . . . . . 15 73 5.2.2. Instruction . . . . . . . . . . . . . . . . . . . . . 16 74 5.2.3. Capabilities, Failure and Logging Information . . . . 20 75 5.3. Operation of Measurement Tasks . . . . . . . . . . . . . 21 76 5.3.1. Starting and Stopping Measurement Tasks . . . . . . . 22 77 5.3.2. Overlapping Measurement Tasks . . . . . . . . . . . . 23 78 5.4. Report Protocol . . . . . . . . . . . . . . . . . . . . . 23 79 5.4.1. Reporting of Subscriber's service parameters . . . . 25 80 5.5. Operation of LMAP over the underlying packet transfer 81 mechanism . . . . . . . . . . . . . . . . . . . . . . . . 25 82 5.6. Items beyond the scope of the initial LMAP work . . . . . 26 83 5.6.1. End-user-controlled measurement system . . . . . . . 28 84 6. Deployment considerations . . . . . . . . . . . . . . . . . . 28 85 6.1. Controller and the measurement system . . . . . . . . . . 28 86 6.2. Measurement Agent . . . . . . . . . . . . . . . . . . . . 29 87 6.2.1. Measurement Agent on a networked device . . . . . . . 30 88 6.2.2. Measurement Agent embedded in site gateway . . . . . 30 89 6.2.3. Measurement Agent embedded behind site NAT /firewall 30 90 6.2.4. Multi-homed Measurement Agent . . . . . . . . . . . . 31 91 6.2.5. Measurement Agent embedded in ISP network . . . . . . 31 92 6.3. Measurement Peer . . . . . . . . . . . . . . . . . . . . 32 93 7. Security considerations . . . . . . . . . . . . . . . . . . . 32 94 8. Privacy considerations . . . . . . . . . . . . . . . . . . . 34 95 8.1. Categories of entities with information of interest . . . 34 96 8.2. Examples of sensitive information . . . . . . . . . . . . 35 97 8.3. Different privacy issues raised by different sorts of 98 Measurement Methods . . . . . . . . . . . . . . . . . . . 36 99 8.4. Privacy analysis of the communication models . . . . . . 37 100 8.4.1. MA Bootstrapping . . . . . . . . . . . . . . . . . . 37 101 8.4.2. Controller <-> Measurement Agent . . . . . . . . . . 38 102 8.4.3. Collector <-> Measurement Agent . . . . . . . . . . . 39 103 8.4.4. Measurement Peer <-> Measurement Agent . . . . . . . 39 104 8.4.5. Measurement Agent . . . . . . . . . . . . . . . . . . 41 105 8.4.6. Storage and reporting of Measurement Results . . . . 42 106 8.5. Threats . . . . . . . . . . . . . . . . . . . . . . . . . 42 107 8.5.1. Surveillance . . . . . . . . . . . . . . . . . . . . 42 108 8.5.2. Stored data compromise . . . . . . . . . . . . . . . 42 109 8.5.3. Correlation and identification . . . . . . . . . . . 43 110 8.5.4. Secondary use and disclosure . . . . . . . . . . . . 43 111 8.6. Mitigations . . . . . . . . . . . . . . . . . . . . . . . 44 112 8.6.1. Data minimisation . . . . . . . . . . . . . . . . . . 44 113 8.6.2. Anonymity . . . . . . . . . . . . . . . . . . . . . . 45 114 8.6.3. Pseudonymity . . . . . . . . . . . . . . . . . . . . 46 115 8.6.4. Other mitigations . . . . . . . . . . . . . . . . . . 46 116 9. IANA considerations . . . . . . . . . . . . . . . . . . . . . 47 117 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 47 118 11. History . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 119 11.1. From -00 to -01 . . . . . . . . . . . . . . . . . . . . 47 120 11.2. From -01 to -02 . . . . . . . . . . . . . . . . . . . . 48 121 11.3. From -02 to -03 . . . . . . . . . . . . . . . . . . . . 49 122 11.4. From -03 to -04 . . . . . . . . . . . . . . . . . . . . 49 123 11.5. From -04 to -05 . . . . . . . . . . . . . . . . . . . . 50 124 11.6. From -05 to -06 . . . . . . . . . . . . . . . . . . . . 51 125 11.7. From -06 to -07 . . . . . . . . . . . . . . . . . . . . 51 126 11.8. From -07 to -08 . . . . . . . . . . . . . . . . . . . . 51 127 11.9. From -08 to -09 . . . . . . . . . . . . . . . . . . . . 51 128 11.10. From -09 to -10 . . . . . . . . . . . . . . . . . . . . 51 129 12. Informative References . . . . . . . . . . . . . . . . . . . 52 130 Appendix A. Appendix: Deployment examples . . . . . . . . . . . 54 131 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 57 133 1. Introduction 135 There is a desire to be able to coordinate the execution of broadband 136 measurements and the collection of measurement results across a large 137 scale set of diverse devices. These devices could be software based 138 agents on PCs, embedded agents in consumer devices (such as TVs or 139 gaming consoles), service provider controlled devices such as set-top 140 boxes and home gateways, or simply dedicated probes. It is expected 141 that such a system could easily comprise 100,000 devices. 142 Measurement devices may also be embedded on a device that is part of 143 an ISP's network, such as a DSLAM (Digital Subscriber Line Access 144 Multiplexer), router, Carrier Grade NAT (Network Address Translator) 145 or ISP Gateway. Such a scale presents unique problems in 146 coordination, execution and measurement result collection. Several 147 use cases have been proposed for large-scale measurements including: 149 o Operators: to help plan their network and identify faults 151 o Regulators: to benchmark several network operators and support 152 public policy development 154 Further details of the use cases can be found in 155 [I-D.ietf-lmap-use-cases]. The LMAP framework should be useful for 156 these, as well as other use cases, such as to help end users run 157 diagnostic checks like a network speed test. 159 The LMAP Framework has three basic elements: Measurement Agents, 160 Controllers and Collectors. 162 Measurement Agents (MAs) initiate the actual measurements, which are 163 called Measurement Tasks in the LMAP terminology. In principle, 164 there are no restrictions on the type of device in which the MA 165 function resides. 167 The Controller instructs one or more MAs and communicates the set of 168 Measurement Tasks an MA should perform and when. For example it may 169 instruct a MA at a home gateway: "Measure the 'UDP latency' with 170 www.example.org; repeat every hour at xx.05". The Controller also 171 manages a MA by instructing it how to report the Measurement Results, 172 for example: "Report results once a day in a batch at 4am". We refer 173 to these as the Measurement Schedule and Report Schedule. 175 The Collector accepts Reports from the MAs with the Results from 176 their Measurement Tasks. Therefore the MA is a device that gets 177 Instructions from the Controller, initiates the Measurement Tasks, 178 and reports to the Collector. The communications between these three 179 LMAP functions are structured according to a Control Protocol and a 180 Report Protocol. 182 The desirable features for a large-scale Measurement Systems we are 183 designing for are: 185 o Standardised - in terms of the Measurement Tasks that they 186 perform, the components, the data models and protocols for 187 transferring information between the components. Amongst other 188 things, standardisation enables meaningful comparisons of 189 measurements made of the same metric at different times and 190 places, and provides the operator of a Measurement System with 191 criteria for evaluation of the different solutions that can be 192 used for various purposes including buying decisions (such as 193 buying the various components from different vendors). Today's 194 systems are proprietary in some or all of these aspects. 196 o Large-scale - [I-D.ietf-lmap-use-cases] envisages Measurement 197 Agents in every home gateway and edge device such as set-top boxes 198 and tablet computers, and located throughout the Internet as well 199 [I-D.ietf-ippm-lmap-path]. It is expected that a Measurement 200 System could easily encompass a few hundred thousand or even 201 millions of Measurement Agents. Existing systems have up to a few 202 thousand MAs (without judging how much further they could scale). 204 o Diversity - a Measurement System should handle Measurement Agents 205 from different vendors, that are in wired and wireless networks, 206 can execute different sorts of Measurement Task, are on devices 207 with IPv4 or IPv6 addresses, and so on. 209 2. Outline of an LMAP-based measurement system 211 In this section we provide an overview of the whole Measurement 212 System. New LMAP-specific terms are capitalised; Section 3 provides 213 a terminology section with a compilation of all the LMAP terms and 214 their definition. Section 4 onwards considers the LMAP components in 215 more detail. 217 Other LMAP specifications will define an information model, the 218 associated data models, and select/extend one or more protocols for 219 the secure communication: firstly, a Control Protocol, from a 220 Controller to instruct Measurement Agents what performance metrics to 221 measure, when to measure them, how/when to report the measurement 222 results to a Collector; secondly, a Report Protocol, for a 223 Measurement Agent to report the results to the Collector. 225 Figure 1 shows the main components of a Measurement System, and the 226 interactions of those components. Some of the components are outside 227 the scope of initial LMAP work. 229 The MA performs Measurement Tasks. In the example shown in Figure 1, 230 the MA is observing existing traffic. Another possibility is for the 231 MA may generate (or receive) traffic specially created for the 232 purpose and measure some metric associated with its transfer. The 233 Appendix shows some examples of possible arrangements of the 234 components. 236 The MAs are pieces of code that can be executed in specialised 237 hardware (hardware probe) or on a general-purpose device (like a PC 238 or mobile phone). A device with a Measurement Agent may have 239 multiple physical interfaces (Wi-Fi, Ethernet, DSL (Digital 240 Subscriber Line); and non-physical interfaces such as PPPoE (Point- 241 to-Point Protocol over Ethernet) or IPsec) and the Measurement Tasks 242 may specify any one of these. 244 The Controller manages a MA through use of the Control Protocol, 245 which transfers the Instruction to the MA. This describes the 246 Measurement Tasks the MA should perform and when. For example the 247 Controller may instruct a MA at a home gateway: "Count the number of 248 TCP SYN packets observed in a 1 minute interval; repeat every hour at 249 xx.05 + Unif[0,180] seconds". The Measurement Schedule determines 250 when the Measurement Tasks are executed. The Controller also manages 251 a MA by instructing it how to report the Measurement Results, for 252 example: "Report results once a day in a batch at 4am + Unif[0,180] 253 seconds; if the end user is active then delay the report 5 minutes". 254 The Report Schedule determines when the Reports are uploaded to the 255 Collector. The Measurement Schedule and Report Schedule can define 256 one-off (non-recurring) actions ("Do measurement now", "Report as 257 soon as possible"), as well as recurring ones. 259 The Collector accepts a Report from a MA with the Measurement Results 260 from its Measurement Tasks. It then provides the Results to a 261 repository (see below). 263 A Measurement Method defines how to measure a Metric of interest. It 264 is very useful to standardise Measurement Methods, so that it is 265 meaningful to compare measurements of the same Metric made at 266 different times and places. It is also useful to define a registry 267 for commonly-used Metrics [I-D.ietf-ippm-metric-registry] so that a 268 Metric with its associated Measurement Method can be referred to 269 simply by its identifier in the registry. The registry will 270 hopefully be referenced by other standards organisations. The 271 Measurement Methods may be defined by the IETF, locally, or by some 272 other standards body. 274 Broadly speaking there are two types of Measurement Method. In both 275 types a Measurement Agent measures a particular Observed Traffic 276 Flow. It may involve a single MA simply observing existing traffic - 277 for example, the Measurement Agent could count bytes or calculate the 278 average loss for a particular flow. On the other hand, a Measurement 279 Method may involve multiple network entities, which perform different 280 roles. For example, a "ping" Measurement Method, to measure the 281 round trip delay , would consist of an MA sending an ICMP (Internet 282 Control Message Protocol) ECHO request to a responder in the 283 Internet. In LMAP terms, the responder is termed a Measurement Peer 284 (MP), meaning that it helps the MA but is not managed by the 285 Controller. Other Measurement Methods involve a second MA, with the 286 Controller instructing the MAs in a coordinated manner. Traffic 287 generated specifically as part of the Measurement Method is termed 288 Measurement Traffic; in the ping example, it is the ICMP ECHO 289 Requests and Replies. The protocols used for the Measurement Traffic 290 are out of the scope of initial LMAP work, and fall within the scope 291 of other IETF WGs such as IPPM (IP Performance Metrics). 293 A Measurement Task is the action performed by a particular MA at a 294 particular time, as the specific instance of its role in a 295 Measurement Method. LMAP is mainly concerned with Measurement Tasks, 296 for instance in terms of its Information Model and Protocols. 298 For Measurement Results to be truly comparable, as might be required 299 by a regulator, not only do the same Measurement Methods need to be 300 used to assess Metrics, but also the set of Measurement Tasks should 301 follow a similar Measurement Schedule and be of similar number. The 302 details of such a characterisation plan are beyond the scope of work 303 in IETF although certainly facilitated by IETF's work. 305 Messages are transferred over a secure Channel. A Control Channel is 306 between the Controller and a MA; the Control Protocol delivers 307 Instruction Messages to the MA and Capabilities, Failure and Logging 308 Information in the reverse direction. A Report Channel is between a 309 MA and Collector, and the Report Protocol delivers Reports to the 310 Collector. 312 Finally we introduce several components that are outside the scope of 313 initial LMAP work and will be provided through existing protocols or 314 applications. They affect how the Measurement System uses the 315 Measurement Results and how it decides what set of Measurement Tasks 316 to perform. As shown in Figure 1, these components are: the 317 bootstrapper, Subscriber parameter database, data analysis tools, and 318 Results repository. 320 The MA needs to be bootstrapped with initial details about its 321 Controller, including authentication credentials. The LMAP work 322 considers the bootstrap process, since it affects the Information 323 Model. However, LMAP does not define a bootstrap protocol, since it 324 is likely to be technology specific and could be defined by the 325 Broadband Forum, CableLabs or IEEE depending on the device. Possible 326 protocols are SNMP (Simple Network Management Protocol), NETCONF 327 (Network Configuration Protocol) or (for Home Gateways) CPE WAN 328 Management Protocol (CWMP) from the Auto Configuration Server (ACS) 329 (as specified in TR-069 [TR-069]). 331 A Subscriber parameter database contains information about the line, 332 such as the customer's broadband contract (perhaps 2, 40 or 80Mb/s), 333 the line technology (DSL or fibre), the time zone where the MA is 334 located, and the type of home gateway and MA. These parameters are 335 already gathered and stored by existing operations systems. They may 336 affect the choice of what Measurement Tasks to run and how to 337 interpret the Measurement Results. For example, a download test 338 suitable for a line with an 80Mb/s contract may overwhelm a 2Mb/s 339 line. 341 A results repository records all Measurement Results in an equivalent 342 form, for example an SQL (Structured Query Language) database, so 343 that they can easily be accessed by the data analysis tools. 345 The data analysis tools receive the results from the Collector or via 346 the Results repository. They might visualise the data or identify 347 which component or link is likely to be the cause of a fault or 348 degradation. This information could help the Controller decide what 349 follow-up Measurement Task to perform in order to diagnose a fault. 350 The data analysis tools also need to understand the Subscriber's 351 service information, for example the broadband contract. 353 +-----------+ +-----------+ ^ 354 |End user or| |End user or| | 355 |Measurement| |Measurement| Non-LMAP 356 | Peer | | Peer | Scope 357 +-----------+ +-----------+ v 358 ^ ^ 359 \ traffic +-------------+ / ^ 360 \...............|.............|........./ | 361 | Measurement | | 362 +----------------->| Agent | | 363 | +-------------+ | 364 | ^ | | 365 | Instruction | | Report | 366 | (over Control | | (over Control Channel) | 367 | Channel) | +---------------+ | 368 | | | | 369 | | | 370 | | v LMAP 371 | +------------+ +------------+ Scope 372 | | Controller | | Collector | | 373 | +------------+ +------------+ v 374 | ^ ^ | ^ 375 | | | | | 376 | | +-------+ | | 377 | | | v | 378 +------------+ +----------+ +--------+ +----------+ | 379 |Bootstrapper| |Subscriber|--->| data |<---| Results | Out 380 +------------+ |parameter | |analysis| |repository| of 381 |database | | tools | +----------+ Scope 382 +----------+ +--------+ | 383 | 384 v 386 Figure 1: Schematic of main elements of an LMAP-based 387 Measurement System 388 (showing the elements in and out of the scope of initial LMAP work) 390 3. Terminology 392 This section defines terminology for LMAP. Please note that defined 393 terms are capitalized. 395 Bootstrap: A process that integrates a Measurement Agent into a 396 Measurement System. 398 Capabilities: Information about the performance measurement 399 capabilities of the MA, in particular the Measurement Method roles 400 and measurement protocol roles that it can perform, and the device 401 hosting the MA, for example its interface type and speed, but not 402 dynamic information. 404 Channel: A bi-directional logical connection that is defined by a 405 specific Controller and MA, or Collector and MA, plus associated 406 security. 408 Collector: A function that receives a Report from a Measurement 409 Agent. 411 Configuration: A process for informing the MA about its MA-ID, 412 (optional) Group-ID and Control Channel. 414 Controller: A function that provides a Measurement Agent with its 415 Instruction. 417 Control Channel: A Channel between a Controller and a MA over which 418 Instruction Messages and Capabilities, Failure and Logging 419 Information are sent. 421 Control Protocol: The protocol delivering Instruction(s) from a 422 Controller to a Measurement Agent. It also delivers Capabilities, 423 Failure and Logging Information from the Measurement Agent to the 424 Controller. It can also be used to update the MA's Configuration. 425 It runs over the Control Channel. 427 Cycle-ID: A tag that is sent by the Controller in an Instruction and 428 echoed by the MA in its Report. The same Cycle-ID is used by several 429 MAs that use the same Measurement Method for a Metric with the same 430 Input Parameters. Hence the Cycle-ID allows the Collector to easily 431 identify Measurement Results that should be comparable. 433 Data Model: The implementation of an Information Model in a 434 particular data modelling language [RFC3444]. 436 Environmental Constraint: A parameter that is measured as part of the 437 Measurement Task, its value determining whether the rest of the 438 Measurement Task proceeds. 440 Failure Information: Information about the MA's failure to action or 441 execute an Instruction, whether concerning Measurement Tasks or 442 Reporting. 444 Group-ID: An identifier of a group of MAs. 446 Information Model: The protocol-neutral definition of the semantics 447 of the Instructions, the Report, the status of the different elements 448 of the Measurement System as well of the events in the system 449 [RFC3444]. 451 Input Parameter: A parameter whose value is left open by the Metric 452 and its Measurement Method and is set to a specific value in a 453 Measurement Task. Altering the value of an Input Parameter does not 454 change the fundamental nature of the Measurement Task. 456 Instruction: The description of Measurement Tasks for a MA to perform 457 and the details of the Report for it to send. It is the collective 458 description of the Measurement Task configurations, the configuration 459 of the Measurement Schedules, the configuration of the Report 460 Channel(s), the configuration of Report Schedule(s), and the details 461 of any suppression. 463 Instruction Message: The message that carries an Instruction from a 464 Controller to a Measurement Agent. 466 Logging Information: Information about the operation of the 467 Measurement Agent and which may be useful for debugging. 469 Measurement Agent (MA): The function that receives Instruction 470 Messages from a Controller and operates the Instruction by executing 471 Measurement Tasks (using protocols outside the initial LMAP work 472 scope and perhaps in concert with one or more other Measurement 473 Agents or Measurement Peers) and (if part of the Instruction) by 474 reporting Measurement Results to a Collector or Collectors. 476 Measurement Agent Identifier (MA-ID): a UUID [RFC4122] that 477 identifies a particular MA and is configured as part of the 478 Bootstrapping process. 480 Measurement Method: The process for assessing the value of a Metric; 481 the process of measuring some performance or reliability parameter 482 associated with the transfer of traffic. 484 Measurement Peer (MP): The function that assists a Measurement Agent 485 with Measurement Tasks and does not have an interface to the 486 Controller or Collector. 488 Measurement Result: The output of a single Measurement Task (the 489 value obtained for the parameter of interest or Metric). 491 Measurement Schedule: The schedule for performing Measurement Tasks. 493 Measurement System: The set of LMAP-defined and related components 494 that are operated by a single organisation, for the purpose of 495 measuring performance aspects of the network. 497 Measurement Task: The action performed by a particular Measurement 498 Agent that consists of the single assessment of a Metric through 499 operation of a Measurement Method role at a particular time, with all 500 of the role's Input Parameters set to specific values. 502 Measurement Traffic: the packet(s) generated by some types of 503 Measurement Method that involve measuring some parameter associated 504 with the transfer of the packet(s). 506 Metric: The quantity related to the performance and reliability of 507 the network that we'd like to know the value of. 509 Observed Traffic Flow: In RFC 7011, a Traffic Flow (or Flow) is 510 defined as a set of packets or frames passing an Observation Point in 511 the network during a certain time interval. All packets belonging to 512 a particular Flow have a set of common properties, such as packet 513 header fields, characteristics, and treatments. A Flow measured by 514 the LMAP system is termed an Observed Traffic Flow. Its properties 515 are summarized and tabulated in Measurement Results (as opposed to 516 raw capture and export). 518 Report: The set of Measurement Results and other associated 519 information (as defined by the Instruction). The Report is sent by a 520 Measurement Agent to a Collector. 522 Report Channel: A Channel between a Collector and a MA over which 523 Report messages are sent. 525 Report Protocol: The protocol delivering Report(s) from a Measurement 526 Agent to a Collector. It runs over the Report Channel. 528 Report Schedule: the schedule for sending Reports to a Collector. 530 Subscriber: An entity (associated with one or more users) that is 531 engaged in a subscription with a service provider. 533 Suppression: the temporary cessation of Measurement Tasks. 535 4. Constraints 537 The LMAP framework makes some important assumptions, which constrain 538 the scope of the initial LMAP work. 540 4.1. The measurement system is under the direction of a single 541 organisation 543 In the LMAP framework, the Measurement System is under the direction 544 of a single organisation that is responsible for any impact that its 545 measurements have on a user's quality of experience and privacy. 546 Clear responsibility is critical given that a misbehaving large-scale 547 Measurement System could potentially harm user experience, user 548 privacy and network security. 550 However, the components of an LMAP Measurement System can be deployed 551 in administrative domains that are not owned by the measuring 552 organisation. Thus, the system of functions deployed by a single 553 organisation constitutes a single LMAP domain which may span 554 ownership or other administrative boundaries. 556 4.2. Each MA may only have a single Controller at any point in time 558 A MA is instructed by one Controller and is in one Measurement 559 System. The constraint avoids different Controllers giving a MA 560 conflicting instructions and so means that the MA does not have to 561 manage contention between multiple Measurement (or Report) Schedules. 562 This simplifies the design of MAs (critical for a large-scale 563 infrastructure) and allows a Measurement Schedule to be tested on 564 specific types of MA before deployment to ensure that the end user 565 experience is not impacted (due to CPU, memory or broadband-product 566 constraints). However, a Measurement System may have several 567 Controllers. 569 5. Protocol Model 571 A protocol model [RFC4101] presents an architectural model for how 572 the protocol operates and needs to answer three basic questions: 574 1. What problem is the protocol trying to achieve? 576 2. What messages are being transmitted and what do they mean? 578 3. What are the important, but unobvious, features of the protocol? 580 An LMAP system goes through the following phases: 582 o a Bootstrapping process before the MA can take part in the other 583 three phases. 585 o a Control Protocol, which delivers Instruction Messages from a 586 Controller to a MA (amongst other things). 588 o the actual Measurement Tasks, which measure some performance or 589 reliability parameter(s) associated with the transfer of packets. 591 o a Report Protocol, which delivers Reports containing the 592 Measurement Results from a MA to a Collector. 594 The diagrams show the various LMAP messages and uses the following 595 convention: 597 o (optional): indicated by round brackets 599 o [potentially repeated]: indicated by square brackets 601 The protocol model is closely related to the Information Model 602 [I-D.ietf-lmap-information-model], which is the abstract definition 603 of the information carried by the protocol. (If there is any 604 difference between this document and the Information Model, the 605 latter is definitive, since it is on the standards track.) The 606 purpose of both is to provide a protocol and device independent view, 607 which can be implemented via specific protocols. LMAP defines a 608 specific Control Protocol and Report Protocol, but others could be 609 defined by other standards bodies or be proprietary. However it is 610 important that they all implement the same Information Model and 611 protocol model, in order to ease the definition, operation and 612 interoperability of large-scale Measurement Systems. 614 5.1. Bootstrapping process 616 The primary purpose of bootstrapping is to enable a MA to be 617 integrated into a Measurement System. The MA retrieves information 618 about itself (like its identity in the Measurement System) and about 619 the Controller, the Controller learns information about the MA, and 620 they learn about security information to communicate (such as 621 certificates and credentials). 623 Whilst this memo considers the bootstrapping process, it is beyond 624 the scope of initial LMAP work to define a bootstrap mechanism, as it 625 depends on the type of device and access. 627 As a result of the bootstrapping process the MA learns information 628 with the following aims ([I-D.ietf-lmap-information-model] defines 629 the consequent list of information elements): 631 o its identifier, either its MA-ID or a device identifier such as 632 one of its MAC or both. 634 o (optionally) a Group-ID. A Group-ID would be shared by several 635 MAs and could be useful for privacy reasons. For instance, 636 reporting the Group-ID and not the MA-ID could hinder tracking of 637 a mobile device 639 o the Control Channel, which is defined by: 641 * the address which identifies the Control Channel, such as the 642 Controller's FQDN (Fully Qualified Domain Name) [RFC1035]) 644 * security information (for example to enable the MA to decrypt 645 the Instruction Message and encrypt messages sent to the 646 Controller) 648 The details of the bootstrapping process are device /access specific. 649 For example, the information could be in the firmware, manually 650 configured or transferred via a protocol like TR-069 [TR-069]. There 651 may be a multi-stage process where the MA contacts a 'hard-coded' 652 address, which replies with the bootstrapping information. 654 The MA must learn its MA-ID before getting an Instruction, either 655 during Bootstrapping or via Configuration (Section 5.2.1). 657 5.2. Control Protocol 659 The primary purpose of the Control Protocol is to allow the 660 Controller to configure a Measurement Agent with an Instruction about 661 what Measurement Tasks to do, when to do them, and how to report the 662 Measurement Results (Section 5.2.2). The Measurement Agent then acts 663 on the Instruction autonomously. The Control Protocol also enables 664 the MA to inform the Controller about its Capabilities and any 665 Failure and Logging Information (Section 5.2.2). Finally, the 666 Control Protocol allows the Controller to update the MA's 667 Configuration. 669 5.2.1. Configuration 671 Configuration allows the Controller to update the MA about some or 672 all of the information that it obtained during the bootstrapping 673 process: the MA-ID, the (optional) Group-ID and the Control Channel. 674 The Measurement System might use Configuration for several reasons. 675 For example, the bootstrapping process could 'hard code' the MA with 676 details of an initial Controller, and then the initial Controller 677 could configure the MA with details about the Controller that sends 678 Instruction Messages. (Note that a MA only has one Control Channel, 679 and so is associated with only one Controller, at any moment.) 681 Note that an implementation may choose to combine Configuration 682 information and an Instruction Message into a single message. 684 +-----------------+ +-------------+ 685 | | | Measurement | 686 | Controller |===================================| Agent | 687 +-----------------+ +-------------+ 689 Configuration information: -> 690 (MA-ID), 691 (Group-ID), 692 (Control Channel) 693 <- Response(details) 695 5.2.2. Instruction 697 The Instruction is the description of the Measurement Tasks for a 698 Measurement Agent to do and the details of the Measurement Reports 699 for it to send. In order to update the Instruction the Controller 700 uses the Control Protocol to send an Instruction Message over the 701 Control Channel. 703 +-----------------+ +-------------+ 704 | | | Measurement | 705 | Controller |===================================| Agent | 706 +-----------------+ +-------------+ 708 Instruction: -> 709 [(Measurement Task configuration 710 URI of Metric( 711 [Input Parameter], 712 (interface), 713 (Cycle-ID))), 714 (Report Channel), 715 (Schedule), 716 (Suppression information)] 717 <- Response(details) 719 The Instruction defines information with the following aims 720 ([I-D.ietf-lmap-information-model] defines the consequent list of 721 information elements): 723 o the Measurement Task configurations, each of which needs: 725 * the Metric, specified as a URI to a registry entry; it includes 726 the specification of a Measurement Method. The registry could 727 be defined by the IETF [I-D.ietf-ippm-metric-registry], locally 728 by the operator of the Measurement System or perhaps by another 729 standards organisation. 731 * the Measurement Method role. For some Measurement Methods, 732 different parties play different roles; for example (figure A3 733 in the Appendix) an iperf sender and receiver. Each Metric and 734 its associated Measurement Method will describe all measurement 735 roles involved in the process. 737 * a boolean flag (suppress or do-not-suppress) indicating if such 738 a Measurement Task is impacted by a Suppression message (see 739 Section 5.2.2.1). Thus, the flag is an Input Parameter. 741 * any Input Parameters that need to be set for the Metric and the 742 Measurement Method. For example, the address of a Measurement 743 Peer (or other Measurement Agent) that may be involved in a 744 Measurement Task , or traffic filters associated with the 745 Observed Traffic Flow. 747 * if the device with the MA has multiple interfaces, then the 748 interface to use (if not defined, then the default interface is 749 used). 751 * optionally, a Cycle-ID. 753 * optionally, the measurement point designation 754 [I-D.ietf-ippm-lmap-path] of the MA and, if applicable, of the 755 MP or other MA. This can be useful for reporting. 757 o configuration of the Schedules, each of which needs: 759 * the timing of when the Measurement Tasks are to be performed, 760 or the Measurement Reports are to be sent. Possible types of 761 timing are periodic, calendar-based periodic, one-off immediate 762 and one-off at a future time 764 o configuration of the Report Channels, each of which needs: 766 * the address of the Collector, for instance its URL 768 * security for this Report Channel, for example the X.509 769 certificate 771 o Suppression information, if any (see Section 5.2.1.1) 773 A single Instruction Message may contain some or all of the above 774 parts. The finest level of granularity possible in an Instruction 775 Message is determined by the implementation and operation of the 776 Control Protocol. For example, a single Instruction Message may add 777 or update an individual Measurement Schedule - or it may only update 778 the complete set of Measurement Schedules; a single Instruction 779 Message may update both Measurement Schedules and Measurement Task 780 configurations - or only one at a time; and so on. However, 781 Suppression information always replaces (rather than adds to) any 782 previous Suppression information. 784 The MA informs the Controller that it has successfully understood the 785 Instruction Message, or that it cannot action the Instruction - for 786 example, if it doesn't include a parameter that is mandatory for the 787 requested Metric and Measurement Method, or it is missing details of 788 the target Collector. 790 The Instruction Message instructs the MA; the Control Protocol does 791 not allow the MA to negotiate, as this would add complexity to the 792 MA, Controller and Control Protocol for little benefit. 794 5.2.2.1. Suppression 796 The Instruction may include Suppression information. The main 797 motivation for Suppression is to enable the Measurement System to 798 eliminate Measurement Traffic, because there is some unexpected 799 network issue for example. There may be other circumstances when 800 Suppression is useful, for example to eliminate inessential Reporting 801 traffic (even if there is no Measurement Traffic). 803 The Suppression information may include any of the following optional 804 fields: 806 o a set of Measurement Tasks to suppress; the others are not 807 suppressed. For example, this could be useful if a particular 808 Measurement Task is overloading a Measurement Peer with 809 Measurement Traffic. 811 o a set of Measurement Schedules to suppress; the others are not 812 suppressed. For example, suppose the Measurement System has 813 defined two Schedules, one with the most critical Measurement 814 Tasks and the other with less critical ones that create a lot of 815 Measurement Traffic, then it may only want to suppress the second. 817 o a set of Reporting Schedules to suppress; the others are not 818 suppressed. This can be particularly useful in the case of a 819 Measurement Method that doesn't generate Measurement Traffic; it 820 may need to continue observing traffic flows but temporarily 821 suppress Reports due to the network footprint of the Reports. 823 o if all the previous fields are included then the MA suppresses the 824 union - in other words, it suppresses the set of Measurement 825 Tasks, the set of Measurement Schedules, and the set of Reporting 826 Schedules. 828 o if the Suppression information includes neither a set of 829 Measurement Tasks nor a set of Measurement Schedules, then the MA 830 does not begin new Measurement Tasks that have the boolean flag 831 set to "suppress"; however, the MA does begin new Measurement 832 Tasks that have the flag set to "do-not-suppress". 834 o a start time, at which suppression begins. If absent, then 835 Suppression begins immediately. 837 o an end time, at which suppression ends. If absent, then 838 Suppression continues until the MA receives an un-Suppress 839 message. 841 o a demand that the MA immediately ends on-going Measurement Task(s) 842 that are tagged for suppression. (Most likely it is appropriate 843 to delete the associated partial Measurement Result(s).) This 844 could be useful in the case of a network emergency so that the 845 operator can eliminate all inessential traffic as rapidly as 846 possible. If absent, the MA completes on-going Measurement Tasks. 848 An un-Suppress message instructs the MA no longer to suppress, 849 meaning that the MA once again begins new Measurement Tasks, 850 according to its Measurement Schedule. 852 Note that Suppression is not intended to permanently stop a 853 Measurement Task (instead, the Controller should send a new 854 Measurement Schedule), nor to permanently disable a MA (instead, some 855 kind of management action is suggested). 857 +-----------------+ +-------------+ 858 | | | Measurement | 859 | Controller |==============================| Agent | 860 +-----------------+ +-------------+ 862 Suppress: 863 [(Measurement Task), -> 864 (Measurement Schedule), 865 [start time], 866 [end time], 867 [on-going suppressed?]] 869 Un-suppress -> 871 5.2.3. Capabilities, Failure and Logging Information 873 The Control Protocol also enables the MA to inform the Controller 874 about various information, such as its Capabilities and any Failures. 875 It is also possible to use a device-specific mechanism which is 876 beyond the scope of the initial LMAP work. 878 Capabilities are information about the MA that the Controller needs 879 to know in order to correctly instruct the MA, such as: 881 o the Measurement Method (roles) that the MA supports 883 o the measurement protocol types and roles that the MA supports 885 o the interfaces that the MA has 887 o the version of the MA 889 o the version of the hardware, firmware or software of the device 890 with the MA 892 o its Instruction (this could be useful if the Controller thinks 893 something has gone wrong, and wants to check what Instruction the 894 MA is using) 896 o but not dynamic information like the currently unused CPU, memory 897 or battery life of the device with the MA. 899 Failure Information concerns why the MA has been unable to execute a 900 Measurement Task or deliver a Report, for example: 902 o the Measurement Task failed to run properly because the MA 903 (unexpectedly) has no spare CPU cycles 905 o the MA failed record the Measurement Results because it 906 (unexpectedly) is out of spare memory 908 o a Report failed to deliver Measurement Results because the 909 Collector (unexpectedly) is not responding 911 o but not if a Measurement Task correctly doesn't start. For 912 example, the first step of some Measurement Methods is for the MA 913 to check there is no cross-traffic. 915 Logging Information concerns how the MA is operating and may help 916 debugging, for example: 918 o the last time the MA ran a Measurement Task 919 o the last time the MA sent a Measurement Report 921 o the last time the MA received an Instruction Message 923 o whether the MA is currently Suppressing Measurement Tasks 925 Capabilities, Failure and Logging Information are sent by the MA, 926 either in response to a request from the Controller (for example, if 927 the Controller forgets what the MA can do or otherwise wants to 928 resynchronize what it knows about the MA), or on its own initiative 929 (for example when the MA first communicates with a Controller or if 930 it becomes capable of a new Measurement Method). Another example of 931 the latter case is if the device with the MA re-boots, then the MA 932 should notify its Controller in case its Instruction needs to be 933 updated; to avoid a "mass calling event" after a widespread power 934 restoration affecting many MAs, it is sensible for an MA to pause for 935 a random delay, perhaps in the range of one minute or so. 937 +-----------------+ +-------------+ 938 | | | Measurement | 939 | Controller |==================================| Agent | 940 +-----------------+ +-------------+ 942 (Instruction: 943 [(Request Capabilities), 944 (Request Failure Information), 945 (Request Logging Information), 946 (Request Instruction)]) -> 947 <- (Capabilities), 948 (Failure Information), 949 (Logging Information), 950 (Instruction) 952 5.3. Operation of Measurement Tasks 954 This LMAP framework is neutral to what the actual Measurement Task 955 is. It does not define Metrics and Measurement Methods, these are 956 defined elsewhere. 958 The MA carries out the Measurement Tasks as instructed, unless it 959 gets an updated Instruction. The MA acts autonomously, in terms of 960 operation of the Measurement Tasks and reporting of the Results; it 961 doesn't do a 'safety check' with the Controller to ask whether it 962 should still continue with the requested Measurement Tasks. 964 The MA may operate Measurement Tasks sequentially or in parallel (see 965 Section 5.3.2). 967 5.3.1. Starting and Stopping Measurement Tasks 969 This LMAP framework does not define a generic start and stop process, 970 since the correct approach depends on the particular Measurement 971 Task; the details are defined as part of each Measurement Method. 972 This section provides some general hints. The MA does not inform the 973 Controller about Measurement Tasks starting and stopping. 975 Before beginning a Measurement Task the MA may want to run a pre- 976 check. (The pre-check could be defined as a separate, preceding Task 977 or as the first part of a larger Task.) 979 For Measurement Tasks that observe existing traffic, action could 980 include: 982 o checking that there is traffic of interest; 984 o checking that the device with the MA has enough resources to 985 execute the Measurement Task reliably. Note that the designer of 986 the Measurement System should ensure that the device's 987 capabilities are normally sufficient to comfortably operate the 988 Measurement Tasks. 990 For Measurement Tasks that generate Measurement Traffic, a pre-check 991 could include: 993 o the MA checking that there is no cross-traffic. In other words, a 994 check that the end-user isn't already sending traffic; 996 o the MA checking with the Measurement Peer (or other Measurement 997 Agent) involved in the Measurement Task that it can handle a new 998 Measurement Task. For example, the Measurement Peer may already 999 be handling many Measurement Tasks with other MAs; 1001 o sending traffic that probes the path to check it isn't overloaded; 1003 o checking that the device with the MA has enough resources to 1004 execute the Measurement Task reliably. 1006 It is possible that similar checks continue during the Measurement 1007 Task, especially one that is long-running and/or creates a lot of 1008 Measurement Traffic, and might lead to it being abandoned whilst in- 1009 progress. A Measurement Task could also be abandoned in response to 1010 a "suppress" message (see Section 5.2.1). Action could include: 1012 o For 'upload' tests, the MA not sending traffic 1013 o For 'download' tests, the MA closing the TCP connection or sending 1014 a TWAMP (Two-Way Active Measurement Protocol) Stop control message 1015 [RFC5357]. 1017 The Controller may want a MA to run the same Measurement Task 1018 indefinitely (for example, "run the 'upload speed' Measurement Task 1019 once an hour until further notice"). To avoid the MA generating 1020 traffic forever after a Controller has permanently failed (or 1021 communications with the Controller have failed), the MA can be 1022 configured with a time limit; if the MA doesn't hear from the 1023 Controller for this length of time, then it stops operating 1024 Measurement Tasks. 1026 5.3.2. Overlapping Measurement Tasks 1028 It is possible that a MA starts a new Measurement Task before another 1029 Measurement Task has completed. This may be intentional (the way 1030 that the Measurement System has designed the Measurement Schedules), 1031 but it could also be unintentional - for instance, if a Measurement 1032 Task has a 'wait for X' step which pauses for an unexpectedly long 1033 time. This document makes no assumptions about the impact of one 1034 Measurement Task on another. 1036 The operator of the Measurement System can handle (or not) 1037 overlapping Measurement Tasks in any way they choose - it is a policy 1038 or implementation issue and not the concern of LMAP. Some possible 1039 approaches are: to configure the MA not to begin the second 1040 Measurement Task; to start the second Measurement Task as usual; for 1041 the action to be an Input Parameter of the Measurement Task; and so 1042 on. 1044 It may be important to include in the Measurement Report the fact 1045 that the Measurement Task overlapped with another. 1047 5.4. Report Protocol 1049 The primary purpose of the Report Protocol is to allow a Measurement 1050 Agent to report its Measurement Results to a Collector, along with 1051 the context in which they were obtained. 1053 +-----------------+ +-------------+ 1054 | | | Measurement | 1055 | Collector |==================================| Agent | 1056 +-----------------+ +-------------+ 1058 <- Report: 1059 [MA-ID &/or Group-ID], 1060 [Measurement Result], 1061 [details of Measurement Task], 1062 [Cycle-ID] 1063 ACK -> 1065 The Report contains: 1067 o the MA-ID or a Group-ID (to anonymise results) 1069 o the actual Measurement Results, including the time they were 1070 measured. In general the time is simply the MA's best estimate 1071 and there is no guarantee on the accuracy or granularity of the 1072 information. It is possible that some specific analysis of a 1073 particular Measurement Method's Results will impose timing 1074 requirements. 1076 o the details of the Measurement Task (to avoid the Collector having 1077 to ask the Controller for this information later). For example, 1078 the interface used for the measurements. 1080 o the Cycle-ID, if one was included in the Instruction. 1082 o perhaps the Subscriber's service parameters (see Section 5.4.1). 1084 o the measurement point designation of the MA and, if applicable, 1085 the MP or other MA, if the information was included in the 1086 Instruction. This numbering system is defined in 1087 [I-D.ietf-ippm-lmap-path] and allows a Measurement Report to 1088 describe abstractly the path measured (for example, "from a MA at 1089 a home gateway to a MA at a DSLAM"). Also, the MA can anonymise 1090 results by including measurement point designations instead of IP 1091 addresses (Section 8.6.2). 1093 The MA sends Reports as defined by the Instruction. It is possible 1094 that the Instruction tells the MA to report the same Results to more 1095 than one Collector, or to report a different subset of Results to 1096 different Collectors. It is also possible that a Measurement Task 1097 may create two (or more) Measurement Results, which could be reported 1098 differently (for example, one Result could be reported periodically, 1099 whilst the second Result could be an alarm that is created as soon as 1100 the measured value of the Metric crosses a threshold and that is 1101 reported immediately). 1103 Optionally, a Report is not sent when there are no Measurement 1104 Results. 1106 In the initial LMAP Information Model and Report Protocol, for 1107 simplicity we assume that all Measurement Results are reported as-is, 1108 but allow extensibility so that a Measurement System (or perhaps a 1109 second phase of LMAP) could allow a MA to: 1111 o label, or perhaps not include, Measurement Results impacted by, 1112 for instance, cross-traffic or a Measurement Peer (or other 1113 Measurement Agent) being busy 1115 o label Measurement Results obtained by a Measurement Task that 1116 overlapped with another 1118 o not report the Measurement Results if the MA believes that they 1119 are invalid 1121 o detail when Suppression started and ended 1123 As discussed in Section 6.1, data analysis of the results should 1124 carefully consider potential bias from any Measurement Results that 1125 are not reported, or from Measurement Results that are reported but 1126 may be invalid. 1128 5.4.1. Reporting of Subscriber's service parameters 1130 The Subscriber's service parameters are information about his/her 1131 broadband contract, line rate and so on. Such information is likely 1132 to be needed to help analyse the Measurement Results, for example to 1133 help decide whether the measured download speed is reasonable. 1135 The information could be transferred directly from the Subscriber 1136 parameter database to the data analysis tools. It may also be 1137 possible to transfer the information via the MA. How (and if) the MA 1138 knows such information is likely to depend on the device type. The 1139 MA could either include the information in a Measurement Report or 1140 separately. 1142 5.5. Operation of LMAP over the underlying packet transfer mechanism 1144 The above sections have described LMAP's protocol model. Other 1145 specifications will define the actual Control and Report Protocols, 1146 possibly operating over an existing protocol, such as REST-style 1147 HTTP(S). It is also possible that a different choice is made for the 1148 Control and Report Protocols, for example NETCONF-YANG [RFC6241] and 1149 IPFIX (Internet Protocol Flow Information Export) [RFC7011] 1150 respectively. 1152 From an LMAP perspective, the Controller needs to know that the MA 1153 has received the Instruction Message, or at least that it needs to be 1154 re-sent as it may have failed to be delivered. Similarly the MA 1155 needs to know about the delivery of Capabilities and Failure 1156 information to the Controller and Reports to the Collector. How this 1157 is done depends on the design of the Control and Report Protocols and 1158 the underlying packet transfer mechanism. 1160 For the Control Protocol, the underlying packet transfer mechanism 1161 could be: 1163 o a 'push' protocol (that is, from the Controller to the MA) 1165 o a multicast protocol (from the Controller to a group of MAs) 1167 o a 'pull' protocol. The MA periodically checks with Controller if 1168 the Instruction has changed and pulls a new Instruction if 1169 necessary. A pull protocol seems attractive for a MA behind a NAT 1170 or firewall (as is typical for a MA on an end-user's device), so 1171 that it can initiate the communications. It also seems attractive 1172 for a MA on a mobile device, where the Controller might not know 1173 how to reach the MA. A pull mechanism is likely to require the MA 1174 to be configured with how frequently it should check in with the 1175 Controller, and perhaps what it should do if the Controller is 1176 unreachable after a certain number of attempts. 1178 o a hybrid protocol. In addition to a pull protocol, the Controller 1179 can also push an alert to the MA that it should immediately pull a 1180 new Instruction. 1182 For the Report Protocol, the underlying packet transfer mechanism 1183 could be: 1185 o a 'push' protocol (that is, from the MA to the Collector) 1187 o perhaps supplemented by the ability for the Collector to 'pull' 1188 Measurement Results from a MA. 1190 5.6. Items beyond the scope of the initial LMAP work 1192 There are several potential interactions between LMAP elements that 1193 are beyond the scope of the initial LMAP work: 1195 1. It does not define a coordination process between MAs. Whilst a 1196 Measurement System may define coordinated Measurement Schedules 1197 across its various MAs, there is no direct coordination between 1198 MAs. 1200 2. It does not define interactions between the Collector and 1201 Controller. It is quite likely that there will be such 1202 interactions, optionally intermediated by the data analysis 1203 tools. For example, if there is an "interesting" Measurement 1204 Result then the Measurement System may want to trigger extra 1205 Measurement Tasks that explore the potential cause in more 1206 detail; or if the Collector unexpectedly does not hear from a MA, 1207 then the Measurement System may want to trigger the Controller to 1208 send a fresh Instruction Message to the MA. 1210 3. It does not define coordination between different Measurement 1211 Systems. For example, it does not define the interaction of a MA 1212 in one Measurement System with a Controller or Collector in a 1213 different Measurement System. Whilst it is likely that the 1214 Control and Report Protocols could be re-used or adapted for this 1215 scenario, any form of coordination between different 1216 organisations involves difficult commercial and technical issues 1217 and so, given the novelty of large-scale measurement efforts, any 1218 form of inter-organisation coordination is outside the scope of 1219 the initial LMAP work. Note that a single MA is instructed by a 1220 single Controller and is only in one Measurement System. 1222 * An interesting scenario is where a home contains two 1223 independent MAs, for example one controlled by a regulator and 1224 one controlled by an ISP. Then the Measurement Traffic of one 1225 MA is treated by the other MA just like any other end-user 1226 traffic. 1228 4. It does not consider how to prevent a malicious party "gaming the 1229 system". For example, where a regulator is running a Measurement 1230 System in order to benchmark operators, a malicious operator 1231 could try to identify the broadband lines that the regulator was 1232 measuring and prioritise that traffic. It is assumed this is a 1233 policy issue and would be dealt with through a code of conduct 1234 for instance. 1236 5. It does not define how to analyse Measurement Results, including 1237 how to interpret missing Results. 1239 6. It does not specifically define a end-user-controlled Measurement 1240 System, see sub-section 5.6.1. 1242 5.6.1. End-user-controlled measurement system 1244 This framework concentrates on the cases where an ISP or a regulator 1245 runs the Measurement System. However, we expect that LMAP 1246 functionality will also be used in the context of an end-user- 1247 controlled Measurement System. There are at least two ways this 1248 could happen (they have various pros and cons): 1250 1. an end-user could somehow request the ISP- (or regulator-) run 1251 Measurement System to test his/her line. The ISP (or regulator) 1252 Controller would then send an Instruction to the MA in the usual 1253 LMAP way. 1255 2. an end-user could deploy their own Measurement System, with their 1256 own MA, Controller and Collector. For example, the user could 1257 implement all three functions onto the same end-user-owned end 1258 device, perhaps by downloading the functions from the ISP or 1259 regulator. Then the LMAP Control and Report Protocols do not 1260 need to be used, but using LMAP's Information Model would still 1261 be beneficial. A Measurement Peer (or other MA involved in a 1262 Measurement Task) could be in the home gateway or outside the 1263 home network; in the latter case the Measurement Peer is highly 1264 likely to be run by a different organisation, which raises extra 1265 privacy considerations. 1267 In both cases there will be some way for the end-user to initiate the 1268 Measurement Task(s). The mechanism is outside the scope of the 1269 initial LMAP work, but could include the user clicking a button on a 1270 GUI or sending a text message. Presumably the user will also be able 1271 to see the Measurement Results, perhaps summarised on a webpage. It 1272 is suggested that these interfaces conform to the LMAP guidance on 1273 privacy in Section 8. 1275 6. Deployment considerations 1277 The Appendix has some examples of possible deployment arrangements of 1278 Measurement Agents and Peers. 1280 6.1. Controller and the measurement system 1282 The Controller should understand both the MA's LMAP Capabilities (for 1283 instance what Metrics and Measurement Methods it can perform) and 1284 about the MA's other capabilities like processing power and memory. 1285 This allows the Controller to make sure that the Measurement Schedule 1286 of Measurement Tasks and the Reporting Schedule are sensible for each 1287 MA that it instructs. 1289 An Instruction is likely to include several Measurement Tasks. 1290 Typically these run at different times, but it is also possible for 1291 them to run at the same time. Some Tasks may be compatible, in that 1292 they do not affect each other's Results, whilst with others great 1293 care would need to be taken. Some Tasks may be complementary. For 1294 example, one Task may be followed by a traceroute Task to the same 1295 destination address, in order to learn the network path that was 1296 measured. 1298 The Controller should ensure that the Measurement Tasks do not have 1299 an adverse effect on the end user. Tasks, especially those that 1300 generate a substantial amount of Measurement Traffic, will often 1301 include a pre-check that the user isn't already sending traffic 1302 (Section 5.3). Another consideration is whether Measurement Traffic 1303 will impact a Subscriber's bill or traffic cap. 1305 A Measurement System may have multiple Controllers (but note the 1306 overriding principle that a single MA is instructed by a single 1307 Controller at any point in time (Section 4.2)). For example, there 1308 could be different Controllers for different types of MA (home 1309 gateways, tablets) or locations (Ipswich, Edinburgh, Paris), for load 1310 balancing or to cope with failure of one Controller. 1312 The measurement system also needs to consider carefully how to 1313 interpret missing Results. The correct interpretation depends on why 1314 the Results are missing (perhaps related to measurement suppression 1315 or delayed Report submission), and potentially on the specifics of 1316 the Measurement Task and Measurement Schedule. For example, the set 1317 of packets represented by a Flow may be empty; that is, an Observed 1318 Traffic Flow may represent zero or more packets. The Flow would 1319 still be reported according to schedule. 1321 6.2. Measurement Agent 1323 The MA should be cautious about resuming Measurement Tasks if it re- 1324 boots or has been off-line for some time, as its Instruction may be 1325 stale. In the former case it also needs to ensure that its clock has 1326 re-set correctly, so that it interprets the Schedule correctly. 1328 If the MA runs out of storage space for Measurement Results or can't 1329 contact the Controller, then the appropriate action is specific to 1330 the device and Measurement System. 1332 The Measurement Agent could take a number of forms: a dedicated 1333 probe, software on a PC, embedded into an appliance, or even embedded 1334 into a gateway. A single site (home, branch office etc.) that is 1335 participating in a measurement could make use of one or multiple 1336 Measurement Agents or Measurement Peers in a single measurement. 1338 The Measurement Agent could be deployed in a variety of locations. 1339 Not all deployment locations are available to every kind of 1340 Measurement Agent. There are also a variety of limitations and 1341 trade-offs depending on the final placement. The next sections 1342 outline some of the locations a Measurement Agent may be deployed. 1343 This is not an exhaustive list and combinations may also apply. 1345 6.2.1. Measurement Agent on a networked device 1347 A MA may be embedded on a device that is directly connected to the 1348 network, such as a MA on a smartphone. Other examples include a MA 1349 downloaded and installed on a subscriber's laptop computer or tablet 1350 when the network service is provided on wired or other wireless radio 1351 technologies, such as Wi-Fi. 1353 6.2.2. Measurement Agent embedded in site gateway 1355 A Measurement Agent embedded with the site gateway, for example a 1356 home router or the edge router of a branch office in a managed 1357 service environment, is one of better places the Measurement Agent 1358 could be deployed. All site-to-ISP traffic would traverse through 1359 the gateway. So, Measurement Methods that measure user traffic could 1360 easily be performed. Similarly, due to this user traffic visibility, 1361 a Measurement Method that generates Measurement Traffic could ensure 1362 it does not compete with user traffic. Generally NAT and firewall 1363 services are built into the gateway, allowing the Measurement Agent 1364 the option to offer its Controller-facing management interface 1365 outside of the NAT/firewall. This placement of the management 1366 interface allows the Controller to unilaterally contact the 1367 Measurement Agent for instructions. However, a Measurement Agent on 1368 a site gateway (whether end-user service-provider owned) will 1369 generally not be directly available for over the top providers, the 1370 regulator, end users or enterprises. 1372 6.2.3. Measurement Agent embedded behind site NAT /firewall 1374 The Measurement Agent could also be embedded behind a NAT, a 1375 firewall, or both. In this case the Controller may not be able to 1376 unilaterally contact the Measurement Agent unless either static port 1377 forwarding or firewall pin holing is configured. Configuring port 1378 forwarding could use protocols such as PCP [RFC6887], TR-069 [TR-069] 1379 or UPnP [UPnP]. To open a pin hole in the firewall, the Measurement 1380 Agent could send keepalives towards the Controller (and perhaps use 1381 these also as a network reachability test). 1383 6.2.4. Multi-homed Measurement Agent 1385 If the device with the Measurement Agent is single homed then there 1386 is no confusion about what interface to measure. Similarly, if the 1387 MA is at the gateway and the gateway only has a single WAN-side and a 1388 single LAN-side interface, there is little confusion - for 1389 Measurement Methods that generate Measurement Traffic, the location 1390 of the other MA or Measurement Peer determines whether the WAN or LAN 1391 is measured. 1393 However, the device with the Measurement Agent may be multi-homed. 1394 For example, a home or campus may be connected to multiple broadband 1395 ISPs, such as a wired and wireless broadband provider, perhaps for 1396 redundancy or load- sharing. It may also be helpful to think of dual 1397 stack IPv4 and IPv6 broadband devices as multi-homed. More 1398 generally, Section 3.2 of [RFC7368] describes dual-stack and multi- 1399 homing topologies that might be encountered in a home network, 1400 [RFC6419] provides the current practices of multi-interfaces hosts, 1401 and the Multiple Interfaces (mif) working group covers cases where 1402 hosts are either directly attached to multiple networks (physical or 1403 virtual) or indirectly (multiple default routers, etc.). In these 1404 cases, there needs to be clarity on which network connectivity option 1405 is being measured. 1407 One possibility is to have a Measurement Agent per interface. Then 1408 the Controller's choice of MA determines which interface is measured. 1409 However, if a MA can measure any of the interfaces, then the 1410 Controller defines in the Instruction which interface the MA should 1411 use for a Measurement Task; if the choice of interface is not defined 1412 then the MA uses the default one. Explicit definition is preferred 1413 if the Measurement System wants to measure the performance of a 1414 particular network, whereas using the default is better if the 1415 Measurement System wants to include the impact of the MA's interface 1416 selection algorithm. In any case, the Measurement Result should 1417 include the network that was measured. 1419 6.2.5. Measurement Agent embedded in ISP network 1421 A MA may be embedded on a device that is part of an ISP's network, 1422 such as a router or switch. Usually the network devices with an 1423 embedded MA will be strategically located, such as a Carrier Grade 1424 NAT or ISP Gateway. [I-D.ietf-ippm-lmap-path] gives many examples 1425 where a MA might be located within a network to provide an 1426 intermediate measurement point on the end-to-end path. Other 1427 examples include a network device whose primary role is to host MA 1428 functions and the necessary measurement protocol. 1430 6.3. Measurement Peer 1432 A Measurement Peer participates in some Measurement Methods. It may 1433 have specific functionality to enable it to participate in a 1434 particular Measurement Method. On the other hand, other Measurement 1435 Methods may require no special functionality. For example if the 1436 Measurement Agent sends a ping to example.com then the server at 1437 example.com plays the role of a Measurement Peer; or if the MA 1438 monitors existing traffic, then the existing end points are 1439 Measurement Peers. 1441 A device may participate in some Measurement Methods as a Measurement 1442 Agent and in others as a Measurement Peer. 1444 Measurement Schedules should account for limited resources in a 1445 Measurement Peer when instructing a MA to execute measurements with a 1446 Measurement Peer. In some measurement protocols, such as [RFC4656] 1447 and [RFC5357], the Measurement Peer can reject a measurement session 1448 or refuse a control connection prior to setting-up a measurement 1449 session and so protect itself from resource exhaustion. This is a 1450 valuable capability because the MP may be used by more than one 1451 organisation. 1453 7. Security considerations 1455 The security of the LMAP framework should protect the interests of 1456 the measurement operator(s), the network user(s) and other actors who 1457 could be impacted by a compromised measurement deployment. The 1458 Measurement System must secure the various components of the system 1459 from unauthorised access or corruption. Much of the general advice 1460 contained in section 6 of [RFC4656] is applicable here. 1462 The process to upgrade the firmware in an MA is outside the scope of 1463 the initial LMAP work, similar to the protocol to bootstrap the MAs 1464 (as specified in the charter). However, systems which provide remote 1465 upgrade must secure authorised access and integrity of the process. 1467 We assume that each Measurement Agent (MA) will receive its 1468 Instructions from a single organisation, which operates the 1469 Controller. These Instructions must be authenticated (to ensure that 1470 they come from the trusted Controller), checked for integrity (to 1471 ensure no-one has tampered with them) and not vulnerable to replay 1472 attacks. If a malicious party can gain control of the MA they can 1473 use it to launch DoS attacks at targets, create a platform for 1474 pervasive monitoring [RFC7258], reduce the end user's quality of 1475 experience and corrupt the Measurement Results that are reported to 1476 the Collector. By altering the Measurement Tasks and/or the address 1477 that Results are reported to, they can also compromise the 1478 confidentiality of the network user and the MA environment (such as 1479 information about the location of devices or their traffic). The 1480 Instruction Messages also need to be encrypted to maintain 1481 confidentiality, as the information might be useful to an attacker. 1483 Reporting by the MA must be encrypted to maintain confidentiality, so 1484 that only the authorised Collector can decrypt the results, to 1485 prevent the leakage of confidential or private information. 1486 Reporting must also be authenticated (to ensure that it comes from a 1487 trusted MA and that the MA reports to a genuine Collector) and not 1488 vulnerable to tampering (which can be ensured through integrity and 1489 replay checks). It must not be possible to fool a MA into injecting 1490 falsified data and the results must also be held and processed 1491 securely after collection and analysis. See section 8.5.2 below for 1492 additional considerations on stored data compromise, and section 8.6 1493 on potential mitigations for compromise. 1495 Since Collectors will be contacted repeatedly by MAs using the 1496 Collection Protocol to convey their recent results, a successful 1497 attack to exhaust the communication resources would prevent a 1498 critical operation: reporting. Therefore, all LMAP Collectors should 1499 implement technical mechanisms to: 1501 o limit the number of reporting connections from a single MA 1502 (simultaneous, and connections per unit time). 1504 o limit the transmission rate from a single MA. 1506 o limit the memory/storage consumed by a single MA's reports. 1508 o efficiently reject reporting connections from unknown sources. 1510 o separate resources if multiple authentication strengths are used, 1511 where the resources should be separated according to each class of 1512 strength. 1514 A corrupted MA could report falsified information to the Collector. 1515 Whether this can be effectively mitigated depends on the platform on 1516 which the MA is deployed, but where the MA is deployed on a customer- 1517 controlled device then the reported data is to some degree inherently 1518 untrustworthy. Further, a sophisticated party could distort some 1519 Measurement Methods, perhaps by dropping or delaying packets for 1520 example. This suggests that the network operator should be cautious 1521 about relying on Measurement Results for action such as refunding 1522 fees if a service level agreement is not met. 1524 As part of the protocol design, it will be decided how LMAP operates 1525 over the underlying protocol (Section 5.5). The choice raises 1526 various security issues, such as how to operate through a NAT and how 1527 to protect the Controller and Collector from denial of service 1528 attacks. 1530 The security mechanisms described above may not be strictly necessary 1531 if the network's design ensures the LMAP components and their 1532 communications are already secured, for example potentially if they 1533 are all part of an ISP's dedicated management network. 1535 Finally, there are three other issues related to security: privacy 1536 (considered in Section 8 below), availability and 'gaming the 1537 system'. While the loss of some MAs may not be considered critical, 1538 the unavailability of the Collector could mean that valuable business 1539 data or data critical to a regulatory process is lost. Similarly, 1540 the unavailability of a Controller could mean that the MAs do not 1541 operate a correct Measurement Schedule. 1543 A malicious party could "game the system". For example, where a 1544 regulator is running a Measurement System in order to benchmark 1545 operators, an operator could try to identify the broadband lines that 1546 the regulator was measuring and prioritise that traffic. Normally, 1547 this potential issue is handled by a code of conduct. It is outside 1548 the scope of the initial LMAP work to consider the issue. 1550 8. Privacy considerations 1552 The LMAP work considers privacy as a core requirement and will ensure 1553 that by default the Control and Report Protocols operate in a 1554 privacy-sensitive manner and that privacy features are well-defined. 1556 This section provides a set of privacy considerations for LMAP. This 1557 section benefits greatly from the timely publication of [RFC6973]. 1558 Privacy and security (Section 7) are related. In some jurisdictions 1559 privacy is called data protection. 1561 We begin with a set of assumptions related to protecting the 1562 sensitive information of individuals and organisations participating 1563 in LMAP-orchestrated measurement and data collection. 1565 8.1. Categories of entities with information of interest 1567 LMAP protocols need to protect the sensitive information of the 1568 following entities, including individuals and organisations who 1569 participate in measurement and collection of results. 1571 o Individual Internet users: Persons who utilise Internet access 1572 services for communications tasks, according to the terms of 1573 service of a service agreement. Such persons may be a service 1574 Subscriber, or have been given permission by the Subscriber to use 1575 the service. 1577 o Internet service providers: Organisations who offer Internet 1578 access service subscriptions, and thus have access to sensitive 1579 information of individuals who choose to use the service. These 1580 organisations desire to protect their Subscribers and their own 1581 sensitive information which may be stored in the process of 1582 performing Measurement Tasks and collecting Results. 1584 o Regulators: Public authorities responsible for exercising 1585 supervision of the electronic communications sector, and which may 1586 have access to sensitive information of individuals who 1587 participate in a measurement campaign. Similarly, regulators 1588 desire to protect the participants and their own sensitive 1589 information. 1591 o Other LMAP system operators: Organisations who operate Measurement 1592 Systems or participate in measurements in some way. 1594 Although privacy is a protection extended to individuals, we include 1595 discussion of ISPs and other LMAP system operators in this section. 1596 These organisations have sensitive information involved in the LMAP 1597 system, and many of the same dangers and mitigations are applicable. 1598 Further, the ISPs store information on their Subscribers beyond that 1599 used in the LMAP system (for instance billing information), and there 1600 should be a benefit in considering all the needs and potential 1601 solutions coherently. 1603 8.2. Examples of sensitive information 1605 This section gives examples of sensitive information which may be 1606 measured or stored in a Measurement System, and which is to be kept 1607 private by default in the LMAP core protocols. 1609 Examples of Subscriber or authorised Internet user sensitive 1610 information: 1612 o Sub-IP layer addresses and names (MAC address, base station ID, 1613 SSID) 1615 o IP address in use 1617 o Personal Identification (real name) 1619 o Location (street address, city) 1621 o Subscribed service parameters 1622 o Contents of traffic (activity, DNS queries, destinations, 1623 equipment types, account info for other services, etc.) 1625 o Status as a study volunteer and Schedule of Measurement Tasks 1627 Examples of Internet Service Provider sensitive information: 1629 o Measurement device identification (equipment ID and IP address) 1631 o Measurement Instructions (choice of measurements) 1633 o Measurement Results (some may be shared, others may be private) 1635 o Measurement Schedule (exact times) 1637 o Network topology (locations, connectivity, redundancy) 1639 o Subscriber billing information, and any of the above Subscriber 1640 information known to the provider. 1642 o Authentication credentials (such as certificates) 1644 Other organisations will have some combination of the lists above. 1645 The LMAP system would not typically expose all of the information 1646 above, but could expose a combination of items which could be 1647 correlated with other pieces collected by an attacker (as discussed 1648 in the section on Threats below). 1650 8.3. Different privacy issues raised by different sorts of Measurement 1651 Methods 1653 Measurement Methods raise different privacy issues depending on 1654 whether they measure traffic created specifically for that purpose, 1655 or whether they measure user traffic. 1657 Measurement Tasks conducted on user traffic store sensitive 1658 information, however briefly this storage may be. We note that some 1659 authorities make a distinction on time of storage, and information 1660 that is kept only temporarily to perform a communications function is 1661 not subject to regulation (for example, active queue management, deep 1662 packet inspection). Such Measurement Tasks could reveal all the 1663 websites a Subscriber visits and the applications and/or services 1664 they use. 1666 Other types of Measurement Task are conducted on traffic which is 1667 created specifically for the purpose. Even if a user host generates 1668 Measurement Traffic, there is limited sensitive information about the 1669 Subscriber present and stored in the Measurement System: 1671 o IP address in use (and possibly sub-IP addresses and names) 1673 o Status as a study volunteer and Schedule of Measurement Tasks 1675 On the other hand, for a service provider the sensitive information 1676 like Measurement Results is the same for all Measurement Tasks. 1678 From the Subscriber perspective, both types of Measurement Task 1679 potentially expose the description of Internet access service and 1680 specific service parameters, such as subscribed rate and type of 1681 access. 1683 8.4. Privacy analysis of the communication models 1685 This section examines each of the protocol exchanges described at a 1686 high level in Section 5 and some example Measurement Tasks, and 1687 identifies specific sensitive information which must be secured 1688 during communication for each case. With the protocol-related 1689 sensitive information identified, we can better consider the threats 1690 described in the following section. 1692 From the privacy perspective, all entities participating in LMAP 1693 protocols can be considered "observers" according to the definition 1694 in [RFC6973]. Their stored information potentially poses a threat to 1695 privacy, especially if one or more of these functional entities has 1696 been compromised. Likewise, all devices on the paths used for 1697 control, reporting, and measurement are also observers. 1699 8.4.1. MA Bootstrapping 1701 Section 5.1 provides the communication model for the Bootstrapping 1702 process. 1704 Although the specification of mechanisms for Bootstrapping the MA are 1705 beyond the initial LMAP work scope, designers should recognize that 1706 the Bootstrapping process is extremely powerful and could cause an MA 1707 to join a new or different LMAP system with a different Controller 1708 and Collector, or simply install new Metrics with associated 1709 Measurement Methods (for example to record DNS queries). A Bootstrap 1710 attack could result in a breach of the LMAP system with significant 1711 sensitive information exposure depending on the capabilities of the 1712 MA, so sufficient security protections are warranted. 1714 The Bootstrapping process provides sensitive information about the 1715 LMAP system and the organisation that operates it, such as 1717 o the MA's identifier (MA-ID) 1718 o the address that identifies the Control Channel, such as the 1719 Controller's FQDN 1721 o Security information for the Control Channel 1723 During the Bootstrap process for an MA located at a single 1724 subscriber's service demarcation point, the MA receives a MA-ID which 1725 is a persistent pseudonym for the Subscriber. Thus, the MA-ID is 1726 considered sensitive information because it could provide the link 1727 between Subscriber identification and Measurements Results. 1729 Also, the Bootstrap process could assign a Group-ID to the MA. The 1730 specific definition of information represented in a Group-ID is to be 1731 determined, but several examples are envisaged including use as a 1732 pseudonym for a set of Subscribers, a class of service, an access 1733 technology, or other important categories. Assignment of a Group-ID 1734 enables anonymisation sets to be formed on the basis of service 1735 type/grade/rates. Thus, the mapping between Group-ID and MA-ID is 1736 considered sensitive information. 1738 8.4.2. Controller <-> Measurement Agent 1740 The high-level communication model for interactions between the LMAP 1741 Controller and Measurement Agent is illustrated in Section 5.2. The 1742 primary purpose of this exchange is to authenticate and task a 1743 Measurement Agent with Measurement Instructions, which the 1744 Measurement Agent then acts on autonomously. 1746 Primarily IP addresses and pseudonyms (MA-ID, Group-ID) are exchanged 1747 with a capability request, then measurement-related information of 1748 interest such as the parameters, schedule, metrics, and IP addresses 1749 of measurement devices. Thus, the measurement Instruction contains 1750 sensitive information which must be secured. For example, the fact 1751 that an ISP is running additional measurements beyond the set 1752 reported externally is sensitive information, as are the additional 1753 Measurements Tasks themselves. The Measurement Schedule is also 1754 sensitive, because an attacker intending to bias the results without 1755 being detected can use this information to great advantage. 1757 An organisation operating the Controller having no service 1758 relationship with a user who hosts the Measurement Agent *could* gain 1759 real-name mapping to a public IP address through user participation 1760 in an LMAP system (this applies to the Measurement Collection 1761 protocol, as well). 1763 8.4.3. Collector <-> Measurement Agent 1765 The high-level communication model for interactions between the 1766 Measurement Agent and Collector is illustrated in Section 5.4. The 1767 primary purpose of this exchange is to authenticate and collect 1768 Measurement Results from a MA, which the MA has measured autonomously 1769 and stored. 1771 The Measurement Results are the additional sensitive information 1772 included in the Collector-MA exchange. Organisations collecting LMAP 1773 measurements have the responsibility for data control. Thus, the 1774 Results and other information communicated in the Collector protocol 1775 must be secured. 1777 8.4.4. Measurement Peer <-> Measurement Agent 1779 A Measurement Method involving Measurement Traffic raises potential 1780 privacy issues, although the specification of the mechanisms is 1781 beyond the scope of the initial LMAP work. The high-level 1782 communications model below illustrates the various exchanges to 1783 execute such a Measurement Method and store the Results. 1785 We note the potential for additional observers in the figures below 1786 by indicating the possible presence of a NAT, which has additional 1787 significance to the protocols and direction of initiation. 1789 The various messages are optional, depending on the nature of the 1790 Measurement Method. It may involve sending Measurement Traffic from 1791 the Measurement Peer to MA, MA to Measurement Peer, or both. 1792 Similarly, a second (or more) MAs may be involved. 1794 _________________ _________________ 1795 | | | | 1796 |Measurement Peer |=========== NAT ? ==========|Measurement Agent| 1797 |_________________| |_________________| 1799 <- (Key Negotiation & 1800 Encryption Setup) 1801 (Encrypted Channel -> 1802 Established) 1803 (Announce capabilities -> 1804 & status) 1805 <- (Select capabilities) 1806 ACK -> 1807 <- (Measurement Request 1808 (MA+MP IPAddrs,set of 1809 Metrics, Schedule)) 1810 ACK -> 1812 Measurement Traffic <> Measurement Traffic 1813 (may/may not be encrypted) (may/may not be encrypted) 1815 <- (Stop Measurement Task) 1817 Measurement Results -> 1818 (if applicable) 1819 <- ACK, Close 1821 This exchange primarily exposes the IP addresses of measurement 1822 devices and the inference of measurement participation from such 1823 traffic. There may be sensitive information on key points in a 1824 service provider's network included. There may also be access to 1825 measurement-related information of interest such as the Metrics, 1826 Schedule, and intermediate results carried in the Measurement Traffic 1827 (usually a set of timestamps). 1829 The Measurement Peer may be able to use traffic analysis (perhaps 1830 combined with traffic injection) to obtain interesting insights about 1831 the Subscriber. As a simple example, if the Measurement Task 1832 includes a pre-check that the end-user isn't already sending traffic, 1833 the Measurement Peer may be able to deduce when the Subscriber is 1834 away on holiday, for example. 1836 If the Measurement Traffic is unencrypted, as found in many systems 1837 today, then both timing and limited results are open to on-path 1838 observers. 1840 8.4.5. Measurement Agent 1842 Some Measurement Methods only involve a single Measurement Agent 1843 observing existing traffic. They raise potential privacy issues, 1844 although the specification of the mechanisms is beyond the scope of 1845 the initial LMAP work. 1847 The high-level communications model below illustrates the collection 1848 of user information of interest with the Measurement Agent performing 1849 the monitoring and storage of the Results. This particular exchange 1850 is for measurement of DNS Response Time, which most frequently uses 1851 UDP transport. 1853 _________________ ____________ 1854 | | | | 1855 | DNS Server |=========== NAT ? ==========*=======| User client| 1856 |_________________| ^ |____________| 1857 ______|_______ 1858 | | 1859 | Measurement | 1860 | Agent | 1861 |______________| 1863 <- Name Resolution Req 1864 (MA+MP IPAddrs, 1865 Desired Domain Name) 1866 Return Record -> 1868 In this particular example, the MA monitors DNS messages in order to 1869 measure that DNS response time. The Measurement Agent may be 1870 embedded in the user host, or it may be located in another device 1871 capable of observing user traffic. The MA learns the IP addresses of 1872 measurement devices and the intent to communicate with or access the 1873 services of a particular domain name, and perhaps also information on 1874 key points in a service provider's network, such as the address of 1875 one of its DNS servers. 1877 In principle, any of the user sensitive information of interest 1878 (listed above) can be collected and stored in the monitoring scenario 1879 and so must be secured. 1881 It would also be possible for a Measurement Agent to source the DNS 1882 query itself. But then there are few privacy concerns. 1884 8.4.6. Storage and reporting of Measurement Results 1886 Although the mechanisms for communicating results (beyond the initial 1887 Collector) are beyond the initial LMAP work scope, there are 1888 potential privacy issues related to a single organisation's storage 1889 and reporting of Measurement Results. Both storage and reporting 1890 functions can help to preserve privacy by implementing the 1891 mitigations described below. 1893 8.5. Threats 1895 This section indicates how each of the threats described in [RFC6973] 1896 apply to the LMAP entities and their communication and storage of 1897 "information of interest". Denial of Service (DOS) and other attacks 1898 described in the Security section represent threats as well, and 1899 these attacks are more effective when sensitive information 1900 protections have been compromised. 1902 8.5.1. Surveillance 1904 Section 5.1.1 of [RFC6973] describes Surveillance as the "observation 1905 or monitoring of and individual's communications or activities." 1906 Hence all Measurement Methods that measure user traffic are a form of 1907 surveillance, with inherent risks. 1909 Measurement Methods which avoid periods of user transmission 1910 indirectly produce a record of times when a subscriber or authorised 1911 user has used their network access service. 1913 Measurement Methods may also utilise and store a Subscriber's 1914 currently assigned IP address when conducting measurements that are 1915 relevant to a specific Subscriber. Since the Measurement Results are 1916 time-stamped, they could provide a record of IP address assignments 1917 over time. 1919 Either of the above pieces of information could be useful in 1920 correlation and identification, described below. 1922 8.5.2. Stored data compromise 1924 Section 5.1.2 of [RFC6973] describes Stored Data Compromise as 1925 resulting from inadequate measures to secure stored data from 1926 unauthorised or inappropriate access. For LMAP systems this includes 1927 deleting or modifying collected measurement records, as well as data 1928 theft. 1930 The primary LMAP entity subject to compromise is the repository, 1931 which stores the Measurement Results; extensive security and privacy 1932 threat mitigations are warranted. The Collector and MA also store 1933 sensitive information temporarily, and need protection. The 1934 communications between the local storage of the Collector and the 1935 repository is beyond the scope of the initial LMAP work, though this 1936 communications channel will certainly need protection as well as the 1937 mass storage itself. 1939 The LMAP Controller may have direct access to storage of Subscriber 1940 information (location, billing, service parameters, etc.) and other 1941 information which the controlling organisation considers private, and 1942 again needs protection. 1944 Note that there is tension between the desire to store all raw 1945 results in the LMAP Collector (for reproducibility and custom 1946 analysis), and the need to protect the privacy of measurement 1947 participants. Many of the compromise mitigations described in 1948 section 8.6 below are most efficient when deployed at the MA, 1949 therefore minimising the risks with stored results. 1951 8.5.3. Correlation and identification 1953 Sections 5.2.1 and 5.2.2 of [RFC6973] describe Correlation as 1954 combining various pieces of information to obtain desired 1955 characteristics of an individual, and Identification as using this 1956 combination to infer identity. 1958 The main risk is that the LMAP system could unwittingly provide a key 1959 piece of the correlation chain, starting with an unknown Subscriber's 1960 IP address and another piece of information. For example, a 1961 Subscriber utilised Internet access from 2000 to 2310 UTC, because 1962 the Measurement Tasks were deferred, or sent a name resolution for 1963 www.example.com at 2300 UTC. 1965 8.5.4. Secondary use and disclosure 1967 Sections 5.2.3 and 5.2.4 of [RFC6973] describes Secondary Use as 1968 unauthorised utilisation of an individual's information for a purpose 1969 the individual did not intend, and Disclosure is when such 1970 information is revealed causing other's notions of the individual to 1971 change, or confidentiality to be violated. 1973 Measurement Methods that measure user traffic are a form of Secondary 1974 Use, and the Subscribers' permission should be obtained beforehand. 1975 It may be necessary to obtain the measured ISP's permission to 1976 conduct measurements, for example when required by the terms and 1977 conditions of the service agreement, and notification is considered 1978 good measurement practice. 1980 For Measurement Methods that measure Measurement Traffic the 1981 Measurement Results provide some limited information about the 1982 Subscriber or ISP and could result in Secondary Uses. For example, 1983 the use of the Results in unauthorised marketing campaigns would 1984 qualify as Secondary Use. Secondary use may break national laws and 1985 regulations, and may violate individual's expectations or desires. 1987 8.6. Mitigations 1989 This section examines the mitigations listed in section 6 of 1990 [RFC6973] and their applicability to LMAP systems. Note that each 1991 section in [RFC6973] identifies the threat categories that each 1992 technique mitigates. 1994 8.6.1. Data minimisation 1996 Section 6.1 of [RFC6973] encourages collecting and storing the 1997 minimal information needed to perform a task. 1999 LMAP results can be useful for general reporting about performance 2000 and for specific troubleshooting. They need different levels of 2001 information detail, as explained in the paragraphs below. 2003 For general results, the results can be aggregated into large 2004 categories (the month of March, all subscribers West of the 2005 Mississippi River). In this case, all individual identifications 2006 (including IP address of the MA) can be excluded, and only relevant 2007 results are provided. However, this implies a filtering process to 2008 reduce the information fields, because greater detail was needed to 2009 conduct the Measurement Tasks in the first place. 2011 For troubleshooting, so that a network operator or end user can 2012 identify a performance issue or failure, potentially all the network 2013 information (IP addresses, equipment IDs, location), Measurement 2014 Schedule, service configuration, Measurement Results, and other 2015 information may assist in the process. This includes the information 2016 needed to conduct the Measurements Tasks, and represents a need where 2017 the maximum relevant information is desirable, therefore the greatest 2018 protections should be applied. This level of detail is greater than 2019 needed for general performance monitoring. 2021 As regards Measurement Methods that measure user traffic, we note 2022 that a user may give temporary permission (to enable detailed 2023 troubleshooting), but withhold permission for them in general. Here 2024 the greatest breadth of sensitive information is potentially exposed, 2025 and the maximum privacy protection must be provided. The Collector 2026 may perform pre-storage minimisation and other mitigations (below) to 2027 help preserve privacy. 2029 For MAs with access to the sensitive information of users (e.g., 2030 within a home or a personal host/handset), it is desirable for the 2031 results collection to minimise the data reported, but also to balance 2032 this desire with the needs of troubleshooting when a service 2033 subscription exists between the user and organisation operating the 2034 measurements. 2036 8.6.2. Anonymity 2038 Section 6.1.1 of [RFC6973] describes a way in which anonymity is 2039 achieved: "there must exist a set of individuals that appear to have 2040 the same attributes as the individual", defined as an "anonymity 2041 set". 2043 Experimental methods for anonymisation of user identifiable data (and 2044 so particularly applicable to Measurement Methods that measure user 2045 traffic) have been identified in [RFC6235]. However, the findings of 2046 several of the same authors is that "there is increasing evidence 2047 that anonymisation applied to network trace or flow data on its own 2048 is insufficient for many data protection applications as in [Bur10]." 2049 Essentially, the details of such Measurement Methods can only be 2050 accessed by closed organisations, and unknown injection attacks are 2051 always less expensive than the protections from them. However, some 2052 forms of summary may protect the user's sensitive information 2053 sufficiently well, and so each Metric must be evaluated in the light 2054 of privacy. 2056 The techniques in [RFC6235] could be applied more successfully in 2057 Measurement Methods that generate Measurement Traffic, where there 2058 are protections from injection attack. The successful attack would 2059 require breaking the integrity protection of the LMAP Reporting 2060 Protocol and injecting Measurement Results (known fingerprint, see 2061 section 3.2 of [RFC6973]) for inclusion with the shared and 2062 anonymised results, then fingerprinting those records to ascertain 2063 the anonymisation process. 2065 Beside anonymisation of measured Results for a specific user or 2066 provider, the value of sensitive information can be further diluted 2067 by summarising the results over many individuals or areas served by 2068 the provider. There is an opportunity enabled by forming anonymity 2069 sets [RFC6973] based on the reference path measurement points in 2070 [I-D.ietf-ippm-lmap-path]. For example, all measurements from the 2071 Subscriber device can be identified as "mp000", instead of using the 2072 IP address or other device information. The same anonymisation 2073 applies to the Internet Service Provider, where their Internet 2074 gateway would be referred to as "mp190". 2076 Another anonymisation technique is for the MA to include its Group-ID 2077 instead of its MA-ID in its Measurement Reports, with several MAs 2078 sharing the same Group-ID. 2080 8.6.3. Pseudonymity 2082 Section 6.1.2 of [RFC6973] indicates that pseudonyms, or nicknames, 2083 are a possible mitigation to revealing one's true identity, since 2084 there is no requirement to use real names in almost all protocols. 2086 A pseudonym for a measurement device's IP address could be an LMAP- 2087 unique equipment ID. However, this would likely be a permanent 2088 handle for the device, and long-term use weakens a pseudonym's power 2089 to obscure identity. 2091 8.6.4. Other mitigations 2093 Data can be de-personalised by blurring it, for example by adding 2094 synthetic data, data-swapping, or perturbing the values in ways that 2095 can be reversed or corrected. 2097 Sections 6.2 and 6.3 of [RFC6973] describe User Participation and 2098 Security, respectively. 2100 Where LMAP measurements involve devices on the Subscriber's premises 2101 or Subscriber-owned equipment, it is essential to secure the 2102 Subscriber's permission with regard to the specific information that 2103 will be collected. The informed consent of the Subscriber (and, if 2104 different, the end user) may be needed, including the specific 2105 purpose of the measurements. The approval process could involve 2106 showing the Subscriber their measured information and results before 2107 instituting periodic collection, or before all instances of 2108 collection, with the option to cancel collection temporarily or 2109 permanently. 2111 It should also be clear who is legally responsible for data 2112 protection (privacy); in some jurisdictions this role is called the 2113 'data controller'. It is always good practice to limit the time of 2114 personal information storage. 2116 Although the details of verification would be impenetrable to most 2117 subscribers, the MA could be architected as an "app" with open 2118 source-code, pre-download and embedded terms of use and agreement on 2119 measurements, and protection from code modifications usually provided 2120 by the app-stores. Further, the app itself could provide data 2121 reduction and temporary storage mitigations as appropriate and 2122 certified through code review. 2124 LMAP protocols, devices, and the information they store clearly need 2125 to be secure from unauthorised access. This is the hand-off between 2126 privacy and security considerations (Section 7). The Data Controller 2127 has the (legal) responsibility to maintain data protections described 2128 in the Subscriber's agreement and agreements with other 2129 organisations. 2131 9. IANA considerations 2133 There are no IANA considerations in this memo. 2135 10. Acknowledgments 2137 This document originated as a merger of three individual drafts: 2138 draft-eardley-lmap-terminology-02, draft-akhter-lmap-framework-00, 2139 and draft-eardley-lmap-framework-02. 2141 Thanks to Juergen Schoenwaelder for his detailed review of the 2142 terminology. Thanks to Charles Cook for a very detailed review of 2143 -02. Thanks to Barbara Stark and Ken Ko for many helpful comments 2144 about later versions. 2146 Thanks to numerous people for much discussion, directly and on the 2147 LMAP list (apologies to those unintentionally omitted): Alan Clark, 2148 Alissa Cooper, Andrea Soppera, Barbara Stark, Benoit Claise, Brian 2149 Trammell, Charles Cook, Dan Romascanu, Dave Thorne, Frode Soerensen, 2150 Greg Mirsky, Guangqing Deng, Jason Weil, Jean-Francois Tremblay, 2151 Jerome Benoit, Joachim Fabini, Juergen Schoenwaelder, Jukka Manner, 2152 Ken Ko, Lingli Deng, Mach Chen, Matt Mathis, Marc Ibrahim, Michael 2153 Bugenhagen, Michael Faath, Nalini Elkins, Radia Perlman, Rolf Winter, 2154 Sam Crawford, Sharam Hakimi, Steve Miller, Ted Lemon, Timothy Carey, 2155 Vaibhav Bajpai, Vero Zheng, William Lupton. 2157 Philip Eardley, Trevor Burbridge and Marcelo Bagnulo work in part on 2158 the Leone research project, which receives funding from the European 2159 Union Seventh Framework Programme [FP7/2007-2013] under grant 2160 agreement number 317647. 2162 11. History 2164 First WG version, copy of draft-folks-lmap-framework-00. 2166 11.1. From -00 to -01 2168 o new sub-section of possible use of Group-IDs for privacy 2170 o tweak to definition of Control protocol 2171 o fix typo in figure in S5.4 2173 11.2. From -01 to -02 2175 o change to INFORMATIONAL track (previous version had typo'd 2176 Standards track) 2178 o new definitions for Capabilities Information and Failure 2179 Information 2181 o clarify that diagrams show LMAP-level information flows. 2182 Underlying protocol could do other interactions, eg to get through 2183 NAT or for Collector to pull a Report 2185 o add hint that after a re-boot should pause random time before re- 2186 register (to avoid mass calling event) 2188 o delete the open issue "what happens if a Controller fails" (normal 2189 methods can handle) 2191 o add some extra words about multiple Tasks in one Schedule 2193 o clarify that new Schedule replaces (rather than adds to) and old 2194 one. Similarly for new configuration of Measurement Tasks or 2195 Report Channels. 2197 o clarify suppression is temporary stop; send a new Schedule to 2198 permanently stop Tasks 2200 o alter suppression so it is ACKed 2202 o add un-suppress message 2204 o expand the text on error reporting, to mention Reporting failures 2205 (as well as failures to action or execute Measurement Task & 2206 Schedule) 2208 o add some text about how to have Tasks running indefinitely 2210 o add that optionally a Report is not sent when there are no 2211 Measurement Results 2213 o add that a Measurement Task may create more than one Measurement 2214 Result 2216 o clarify /amend /expand that Reports include the "raw" Measurement 2217 Results - any pre-processing is left for lmap2.0 2219 o add some cautionary words about what if the Collector unexpectedly 2220 doesn't hear from a MA 2222 o add some extra words about the potential impact of Measurement 2223 Tasks 2225 o clarified various aspects of the privacy section 2227 o updated references 2229 o minor tweaks 2231 11.3. From -02 to -03 2233 o alignment with the Information Model [burbridge-lmap-information- 2234 model] as this is agreed as a WG document 2236 o One-off and periodic Measurement Schedules are kept separate, so 2237 that they can be updated independently 2239 o Measurement Suppression in a separate sub-section. Can now 2240 optionally include particular Measurement Tasks &/or Schedules to 2241 suppress, and start/stop time 2243 o for clarity, concept of Channel split into Control, Report and MA- 2244 to-Controller Channels 2246 o numerous editorial changes, mainly arising from a very detailed 2247 review by Charles Cook 2249 o 2251 11.4. From -03 to -04 2253 o updates following the WG Last Call, with the proposed consensus on 2254 the various issues as detailed in 2255 http://tools.ietf.org/agenda/89/slides/slides-89-lmap-2.pdf. In 2256 particular: 2258 o tweaked definitions, especially of Measurement Agent and 2259 Measurement Peer 2261 o Instruction - left to each implementation & deployment of LMAP to 2262 decide on the granularity at which an Instruction Message works 2264 o words added about overlapping Measurement Tasks (Measurement 2265 System can handle any way they choose; Report should mention if 2266 the Task overlapped with another) 2268 o Suppression: no defined impact on Passive Measurement Task; extra 2269 option to suppress on-going Active Measurement Tasks; suppression 2270 doesn't go to Measurement Peer, since they don't understand 2271 Instructions 2273 o new concept of Data Transfer Task (and therefore adjustment of the 2274 Channel concept) 2276 o enhancement of Results with Subscriber's service parameters - 2277 could be useful, don't define how but can be included in Report to 2278 various other sections 2280 o various other smaller improvements, arising from the WGLC 2282 o Appendix added with examples of Measurement Agents and Peers in 2283 various deployment scenarios. To help clarify what these terms 2284 mean. 2286 11.5. From -04 to -05 2288 o clarified various scoping comments by using the phrase "scope of 2289 initial LMAP work" (avoiding "scope of LMAP WG" since this may 2290 change in the future) 2292 o added a Configuration Protocol - allows the Controller to update 2293 the MA about information that it obtained during the bootstrapping 2294 process (for consistency with Information Model) 2296 o Removed over-detailed information about the relationship between 2297 the different items in Instruction, as this seems more appropriate 2298 for the information model. Clarified that the lists given are 2299 about the aims and not a list of information elements (these will 2300 be defined in draft-ietf-information-model). 2302 o the Measurement Method, specified as a URI to a registry entry - 2303 rather than a URN 2305 o MA configured with time limit after which, if it hasn't heard from 2306 Controller, then it stops running Measurement Tasks (rather than 2307 this being part of a Schedule) 2309 o clarified there is no distinction between how capabilities, 2310 failure and logging information are transferred (all can be when 2311 requested by Controller or by MA on its own initiative). 2313 o removed mention of Data Transfer Tasks. This abstraction is left 2314 to the information model i-d 2316 o added Deployment sub-section about Measurement Agent embedded in 2317 ISP Network 2319 o various other smaller improvements, arising from the 2nd WGLC 2321 11.6. From -05 to -06 2323 o clarified terminlogy around Measurement Methods and Tasks. Since 2324 within a Method there may be several different roles (requester 2325 and responder, for instance) 2327 o Suppression: there is now the concept of a flag (boolean) which 2328 indicates whether a Task is by default gets suppressed or not. 2329 The optional suppression message (with list of specific tasks 2330 /schedules to suppress) over-rides this flag. 2332 o The previous bullet also means there is no need to make a 2333 distinction between active and passive Measurement Tasks, so this 2334 distinction is removed. 2336 o removed Configuration Protocol - Configuration is part of the 2337 Instruction and so uses the Control Protocol. 2339 11.7. From -06 to -07 2341 o Clarifications and nits 2343 11.8. From -07 to -08 2345 o Clarifications resulting from WG 3rd LC, as discussed in 2346 https://tools.ietf.org/agenda/90/slides/slides-90-lmap-0.pdf, plus 2347 comments made in the IETF-90 meeting. 2349 o added mention of "measurement point designations" in Measurement 2350 Task configuration and Report Protocol. 2352 11.9. From -08 to -09 2354 o Clarifications and changes from the AD review (Benoit Claise) and 2355 security directorate review (Radia Perlman). 2357 11.10. From -09 to -10 2359 o More changes from the AD review (Benoit Claise). 2361 12. Informative References 2363 [Bur10] Burkhart, M., Schatzmann, D., Trammell, B., and E. Boschi, 2364 "The Role of Network Trace anonymisation Under Attack", 2365 January 2010. 2367 [TR-069] TR-069, , "CPE WAN Management Protocol", 2368 http://www.broadband-forum.org/technical/trlist.php, 2369 November 2013. 2371 [UPnP] ISO/IEC 29341-x, , "UPnP Device Architecture and UPnP 2372 Device Control Protocols specifications", 2373 http://upnp.org/sdcps-and-certification/standards/, 2011. 2375 [RFC1035] Mockapetris, P., "Domain names - implementation and 2376 specification", STD 13, RFC 1035, November 1987. 2378 [RFC4101] Rescorla, E. and IAB, "Writing Protocol Models", RFC 4101, 2379 June 2005. 2381 [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally 2382 Unique IDentifier (UUID) URN Namespace", RFC 4122, July 2383 2005. 2385 [RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J., and A. 2386 Bierman, "Network Configuration Protocol (NETCONF)", RFC 2387 6241, June 2011. 2389 [RFC7011] Claise, B., Trammell, B., and P. Aitken, "Specification of 2390 the IP Flow Information Export (IPFIX) Protocol for the 2391 Exchange of Flow Information", STD 77, RFC 7011, September 2392 2013. 2394 [RFC7368] Chown, T., Arkko, J., Brandt, A., Troan, O., and J. Weil, 2395 "IPv6 Home Networking Architecture Principles", RFC 7368, 2396 October 2014. 2398 [RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an 2399 Attack", BCP 188, RFC 7258, May 2014. 2401 [I-D.ietf-lmap-use-cases] 2402 Linsner, M., Eardley, P., Burbridge, T., and F. Sorensen, 2403 "Large-Scale Broadband Measurement Use Cases", draft-ietf- 2404 lmap-use-cases-05 (work in progress), November 2014. 2406 [I-D.ietf-ippm-metric-registry] 2407 Bagnulo, M., Claise, B., Eardley, P., Morton, A., and A. 2408 Akhter, "Registry for Performance Metrics", draft-ietf- 2409 ippm-metric-registry-01 (work in progress), September 2410 2014. 2412 [RFC6419] Wasserman, M. and P. Seite, "Current Practices for 2413 Multiple-Interface Hosts", RFC 6419, November 2011. 2415 [RFC6887] Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P. 2416 Selkirk, "Port Control Protocol (PCP)", RFC 6887, April 2417 2013. 2419 [I-D.ietf-lmap-information-model] 2420 Burbridge, T., Eardley, P., Bagnulo, M., and J. 2421 Schoenwaelder, "Information Model for Large-Scale 2422 Measurement Platforms (LMAP)", draft-ietf-lmap- 2423 information-model-03 (work in progress), January 2015. 2425 [RFC6235] Boschi, E. and B. Trammell, "IP Flow Anonymization 2426 Support", RFC 6235, May 2011. 2428 [RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J., 2429 Morris, J., Hansen, M., and R. Smith, "Privacy 2430 Considerations for Internet Protocols", RFC 6973, July 2431 2013. 2433 [I-D.ietf-ippm-lmap-path] 2434 Bagnulo, M., Burbridge, T., Crawford, S., Eardley, P., and 2435 A. Morton, "A Reference Path and Measurement Points for 2436 Large-Scale Measurement of Broadband Performance", draft- 2437 ietf-ippm-lmap-path-07 (work in progress), October 2014. 2439 [RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M. 2440 Zekauskas, "A One-way Active Measurement Protocol 2441 (OWAMP)", RFC 4656, September 2006. 2443 [RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J. 2444 Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)", 2445 RFC 5357, October 2008. 2447 [RFC3444] Pras, A. and J. Schoenwaelder, "On the Difference between 2448 Information Models and Data Models", RFC 3444, January 2449 2003. 2451 Appendix A. Appendix: Deployment examples 2453 In this section we describe some deployment scenarios that are 2454 feasible within the LMAP framework defined in this document. 2456 A very simple example of a Measurement Peer (MP) is a web server that 2457 the MA is downloading a web page from (such as www.example.com) in 2458 order to perform a speed test. The web server is a MP and from its 2459 perspective, the MA is just another client; the MP doesn't have a 2460 specific function for assisting measurements. This is described in 2461 the figure A1. 2463 ^ 2464 +----------------+ Web Traffic +----------------+ non-LMAP 2465 |MA: Web Client |<------------>| MP: Web Server | Scope 2466 | | +----------------+ | 2467 ...|................|....................................V... 2468 | LMAP interface | ^ 2469 +----------------+ | 2470 ^ | | 2471 Instruction | | Report | 2472 | +-----------------+ | 2473 | | | 2474 | v LMAP 2475 +------------+ +------------+ Scope 2476 | Controller | | Collector | | 2477 +------------+ +------------+ V 2479 Figure A1: Schematic of LMAP-based Measurement System, 2480 with Web server as Measurement Peer 2482 Another case that is slightly different than this would be the one of 2483 a TWAMP-responder. This is also a MP, with a helper function, the 2484 TWAMP server, which is specially deployed to assist the MAs that 2485 perform TWAMP tests. Another example is with a ping server, as 2486 described in Section 2. 2488 A further example is the case of a traceroute like measurement. In 2489 this case, for each packet sent, the router where the TTL expires is 2490 performing the MP function. So for a given Measurement Task, there 2491 is one MA involved and several MPs, one per hop. 2493 In figure A2 we depict the case of an OWAMP (One-Way Active 2494 Measurement Protocol) responder acting as an MP. In this case, the 2495 helper function in addition reports results back to the MA. So it 2496 has both a data plane and control interface with the MA. 2498 +----------------+ OWAMP +----------------+ ^ 2499 | MA: OWAMP |<--control--->| MP: | | 2500 | control-client |-test-traffic>| OWAMP server & | non-LMAP 2501 | fetch-client & |<----fetch----| session-rec'ver| Scope 2502 | session-sender | | | | 2503 | | +----------------+ | 2504 ...|................|....................................v... 2505 | LMAP interface | ^ 2506 +----------------+ | 2507 ^ | | 2508 Instruction | | Report | 2509 | +-----------------+ | 2510 | | | 2511 | v LMAP 2512 +------------+ +------------+ Scope 2513 | Controller | | Collector | | 2514 +------------+ +------------+ v 2516 Figure A2: Schematic of LMAP-based Measurement System, 2517 with OWAMP server as Measurement Peer 2519 However, it is also possible to use two Measurement Agents when 2520 performing one way Measurement Tasks, as described in figure A3 2521 below. Both MAs are instructed by the Controller: MA-1 to send the 2522 traffic and MA-2 to measure the received traffic and send Reports to 2523 the Collector. Note that the Measurement Task at MA-2 can listen for 2524 traffic from MA-1 and respond multiple times without having to be 2525 rescheduled. 2527 +----------------+ +----------------+ ^ 2528 | MA-1: | | MA-2: | non-LMAP 2529 | iperf -u sender|-UDP traffic->| iperf -u recvr | Scope 2530 | | | | v 2531 ...|................|..............|................|....v... 2532 | LMAP interface | | LMAP interface | ^ 2533 +----------------+ +----------------+ | 2534 ^ ^ | | 2535 Instruction | Instruction{Report} | | Report | 2536 {task, | +-------------------+ | | 2537 schedule} | | | | 2538 | | v LMAP 2539 +------------+ +------------+ Scope 2540 | Controller | | Collector | | 2541 +------------+ +------------+ v 2543 Figure A3: Schematic of LMAP-based Measurement System, 2544 with two Measurement Agents cooperating to measure UDP traffic 2546 Next, we consider Measurement Methods that measure user traffic. 2547 Traffic generated in one point in the network flowing towards a given 2548 destination and the traffic is observed in some point along the path. 2549 One way to implement this is that the endpoints generating and 2550 receiving the traffic are not instructed by the Controller; hence 2551 they are MPs. The MA is located along the path with a monitor 2552 function that measures the traffic. The MA is instructed by the 2553 Controller to monitor that particular traffic and to send the Report 2554 to the Collector. It is depicted in figure A4 below. 2556 +--------+ +----------------+ +--------+ ^ 2557 |End user| | MA: Monitor | |End user| | 2558 | or MP |<--|----------------|--traffic-->| or MP | non-LMAP 2559 | | | | | | Scope 2560 +--------+ | | +--------+ | 2561 ...|................|............................v.. 2562 | LMAP interface | ^ 2563 +----------------+ | 2564 ^ | | 2565 Instruction | | Report | 2566 | +-----------------+ | 2567 | | | 2568 | v LMAP 2569 +------------+ +------------+ Scope 2570 | Controller | | Collector | | 2571 +------------+ +------------+ v 2573 Figure A4: Schematic of LMAP-based Measurement System, 2574 with a Measurement Agent monitoring traffic 2576 Authors' Addresses 2578 Philip Eardley 2579 BT 2580 Adastral Park, Martlesham Heath 2581 Ipswich 2582 ENGLAND 2584 Email: philip.eardley@bt.com 2586 Al Morton 2587 AT&T Labs 2588 200 Laurel Avenue South 2589 Middletown, NJ 2590 USA 2592 Email: acmorton@att.com 2593 Marcelo Bagnulo 2594 Universidad Carlos III de Madrid 2595 Av. Universidad 30 2596 Leganes, Madrid 28911 2597 SPAIN 2599 Phone: 34 91 6249500 2600 Email: marcelo@it.uc3m.es 2601 URI: http://www.it.uc3m.es 2603 Trevor Burbridge 2604 BT 2605 Adastral Park, Martlesham Heath 2606 Ipswich 2607 ENGLAND 2609 Email: trevor.burbridge@bt.com 2611 Paul Aitken 2612 Brocade 2613 Edinburgh, Scotland EH6 6LX 2614 UK 2616 Email: paitken@brocade.com 2618 Aamer Akhter 2619 LiveAction 2620 118 Timber Hitch 2621 Cary, NC 2622 USA 2624 Email: aakhter@gmail.com